CY14B064PA-SFXIT [INFINEON]

nvSRAM (non-volatile SRAM);
CY14B064PA-SFXIT
型号: CY14B064PA-SFXIT
厂家: Infineon    Infineon
描述:

nvSRAM (non-volatile SRAM)

静态存储器 光电二极管 内存集成电路
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中文:  中文翻译
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Please note that Cypress is an Infineon Technologies Company.  
The document following this cover page is marked as “Cypress” document as this is the  
company that originally developed the product. Please note that Infineon will continue  
to offer the product to new and existing customers as part of the Infineon product  
portfolio.  
Continuity of document content  
The fact that Infineon offers the following product as part of the Infineon product  
portfolio does not lead to any changes to this document. Future revisions will occur  
when appropriate, and any changes will be set out on the document history page.  
Continuity of ordering part numbers  
Infineon continues to support existing part numbers. Please continue to use the  
ordering part numbers listed in the datasheet for ordering.  
www.infineon.com  
CY14C064PA  
CY14B064PA  
CY14E064PA  
64-Kbit (8 K × 8) SPI nvSRAM  
with Real Time Clock  
64-Kbit (8  
K × 8) SPI nvSRAM with Real Time Clock  
Write protection  
Features  
Hardware protection using Write Protect (WP) pin  
Software protection using Write Disable instruction  
Software block protection for 1/4, 1/2, or entire array  
64-Kbit nonvolatile static random access memory (nvSRAM)  
Internally organized as 8 K × 8  
STORE to QuantumTrap nonvolatile elements initiated  
automatically on power-down (AutoStore) or by using SPI  
instruction (Software STORE) or HSB pin (Hardware  
STORE)  
RECALLtoSRAMinitiatedonpower-up(PowerUpRECALL)  
or by SPI instruction (Software RECALL)  
Low power consumption  
Average active current of 3 mA at 40 MHz operation  
Average standby mode current of 250 A  
Sleep mode current of 8 A  
Industry standard configurations  
Operating voltages:  
• CY14C064PA : VCC = 2.4 V to 2.6 V  
• CY14B064PA : VCC = 2.7 V to 3.6 V  
• CY14E064PA : VCC = 4.5 V to 5.5 V  
Industrial temperature  
Automatic STORE on power-down with a small capacitor  
High reliability  
Infinite read, write, and RECALL cycles  
1 million STORE cycles to QuantumTrap  
Data retention: 20 years at 85C  
16-pin small outline integrated circuit (SOIC) package  
Restriction of hazardous substances (RoHS) compliant  
Real time clock (RTC)  
Full-featured RTC  
Watchdog timer  
Clock alarm with programmable interrupts  
Backup power fail indication  
Overview  
The Cypress CY14X064PA combines a 64 Kbit nvSRAM[1] with  
a full-featured RTC in a monolithic integrated circuit with serial  
SPI interface. The memory is organized as 8 K words of 8 bits  
each. The embedded nonvolatile elements incorporate the  
QuantumTrap technology, creating the world’s most reliable  
nonvolatile memory. The SRAM provides infinite read and write  
cycles, while the QuantumTrap cells provide highly reliable  
nonvolatile storage of data. Data transfers from SRAM to the  
nonvolatile elements (STORE operation) takes place  
automatically at power-down. On power-up, data is restored to  
the SRAM from the nonvolatile memory (RECALL operation).  
You can also initiate the STORE and RECALL operations  
through SPI instruction.  
Square wave output with programmable frequency (1 Hz,  
512 Hz, 4096 Hz, 32.768 kHz)  
Capacitor or battery backup for RTC  
Backup current of 0.45 A (typical)  
40 MHz, and 104 MHz High-speed serial peripheral interface  
(SPI)  
40 MHz clock rate SPI write and read with zero cycle delay  
104 MHz clock rate SPI write and read (with special fast read  
instructions)  
Supports SPI mode 0 (0,0) and mode 3 (1,1)  
SPI access to special functions  
Nonvolatile STORE/RECALL  
8-byte serial number  
Manufacturer ID and Product ID  
Sleep mode  
For a complete list of related documentation, click here.  
VRTCcap VRTCbat  
VCC VCAP  
Logic Block Diagram  
Serial Number  
8 x 8  
Power Control  
Block  
Manufacturer ID /  
Product ID  
QuantumTrap  
8 K x 8  
SLEEP  
STORE  
RECALL  
SRAM  
8 K x 8  
RDSN/WRSN/RDID  
READ/WRITE  
SI  
CS  
Memory  
Data &  
Address  
Control  
SPI Control Logic  
Write Protection  
Instruction decoder  
STORE/RECALL/ASENB/ASDISB  
SCK  
WP  
SO  
WRSR/RDSR/WREN  
RDRTC/WRTC  
Status Register  
Xin  
RTC Control Logic  
Registers  
INT/SQW  
Xout  
Counters  
Note  
1. This device will be referred to as nvSRAM throughout the document.  
Cypress Semiconductor Corporation  
Document Number: 001-68249 Rev. *H  
198 Champion Court  
San Jose, CA 95134-1709  
408-943-2600  
Revised January 16, 2018  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Contents  
Pinout ................................................................................3  
Pin Definitions ..................................................................3  
Device Operation ..............................................................4  
SRAM Write .................................................................4  
SRAM Read ................................................................4  
STORE Operation .......................................................4  
AutoStore Operation ....................................................4  
Software STORE Operation ........................................5  
Hardware STORE and HSB pin Operation .................5  
RECALL Operation ......................................................5  
Hardware RECALL (Power Up) ...................................5  
Software RECALL .......................................................5  
Disabling and Enabling AutoStore ...............................5  
Serial Peripheral Interface ...............................................6  
SPI Overview ...............................................................6  
SPI Modes .........................................................................7  
SPI Operating Features ....................................................8  
Power-Up ....................................................................8  
Power Down ................................................................8  
Active Power and Standby Power Modes ...................8  
SPI Functional Description ..............................................9  
Status Register ...............................................................10  
Read Status Register (RDSR) Instruction .................10  
Fast Read Status Register  
(FAST_RDSR) Instruction .........................................10  
Write Status Register (WRSR) Instruction ................10  
Write Protection and Block Protection .........................11  
Write Enable (WREN) Instruction ..............................11  
Write Disable (WRDI) Instruction ..............................12  
Block Protection ........................................................12  
Hardware Write Protection (WP Pin) .........................12  
Memory Access ..............................................................12  
Read Sequence (READ) Instruction ..........................12  
Fast Read Sequence (FAST_READ) Instruction ......12  
Write Sequence (WRITE) Instruction ........................13  
RTC Access .....................................................................15  
READ RTC (RDRTC) Instruction ..............................15  
Fast Read Sequence (FAST_RDRTC) Instruction ....15  
WRITE RTC (WRTC) Instruction ...............................16  
nvSRAM Special Instructions ........................................17  
Software STORE (STORE) Instruction .....................17  
Software RECALL (RECALL) Instruction ..................17  
AutoStore Enable (ASENB) Instruction .....................17  
AutoStore Disable (ASDISB) Instruction ...................17  
Special Instructions .......................................................17  
SLEEP Instruction .....................................................17  
Serial Number .................................................................18  
WRSN (Serial Number Write) Instruction ..................18  
RDSN (Serial Number Read) Instruction ...................19  
FAST_RDSN  
RDID (Device ID Read) Instruction ...........................20  
FAST_RDID (Fast Device ID Read) Instruction ........21  
HOLD Pin Operation .................................................21  
Real Time Clock Operation ............................................22  
nvTIME Operation .....................................................22  
Clock Operations .......................................................22  
Reading the Clock .....................................................22  
Setting the Clock .......................................................22  
Backup Power ...........................................................22  
Stopping and Starting the Oscillator ..........................22  
Calibrating the Clock .................................................23  
Alarm .........................................................................23  
Watchdog Timer ........................................................23  
Programmable Square Wave Generator ...................24  
Power Monitor ...........................................................24  
Backup Power Monitor ..............................................24  
Interrupts ...................................................................24  
Interrupt Register .......................................................24  
Flags Register ...........................................................25  
RTC External Components .......................................26  
PCB Design Considerations for RTC ............................27  
Layout requirements ..................................................27  
Maximum Ratings ...........................................................32  
Operating Range .............................................................32  
DC Electrical Characteristics ........................................32  
Data Retention and Endurance .....................................33  
Capacitance ....................................................................33  
Thermal Resistance ........................................................33  
AC Test Loads and Waveforms .....................................34  
AC Test Conditions ........................................................34  
RTC Characteristics .......................................................35  
AC Switching Characteristics .......................................35  
Switching Waveforms ....................................................36  
AutoStore or Power-Up RECALL ..................................37  
Switching Waveforms ....................................................37  
Software Controlled STORE/RECALL Cycles ..............38  
Switching Waveforms ....................................................38  
Hardware STORE Cycle .................................................39  
Switching Waveforms ....................................................39  
Ordering Information ......................................................40  
Ordering Code Definitions .........................................40  
Package Diagram ............................................................41  
Acronyms ........................................................................42  
Document Conventions .................................................42  
Units of Measure .......................................................42  
Document History Page .................................................43  
Sales, Solutions, and Legal Information ......................44  
Worldwide Sales and Design Support .......................44  
Products ....................................................................44  
PSoC® Solutions ......................................................44  
Cypress Developer Community .................................44  
Technical Support .....................................................44  
(Fast Serial Number Read) Instruction ......................19  
Device ID .........................................................................20  
Document Number: 001-68249 Rev. *H  
Page 2 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Pinout  
Figure 1. 16-pin SOIC pinout  
V
16  
15  
14  
13  
12  
NC  
1
2
CC  
V
INT/SQW  
RTCbat  
X
V
out  
3
4
5
6
7
8
CAP  
Top View  
X
SO  
SI  
in  
not to scale  
WP  
HOLD  
SCK  
CS  
11  
10  
V
RTCcap  
V
SS  
9
HSB  
Pin Definitions  
Pin Name  
I/O Type  
Description  
CS  
Input  
Chip select: Activates the device when pulled LOW. Driving this pin HIGH puts the device in low power  
standby mode.  
SCK  
Input  
Serial clock: Runs at speeds up to a maximum of fSCK. Serial input is latched at the rising edge of this  
clock. Serial output is driven at the falling edge of the clock.  
SI  
SO  
Input  
Output  
Input  
Serial input: Pin for input of all SPI instructions and data.  
Serial output: Pin for output of data through SPI.  
Write Protect: Implements hardware write protection in SPI.  
HOLD pin: Suspends Serial Operation.  
WP  
HOLD  
HSB  
Input  
Input/Output Hardware STORE Busy: Output: Indicates busy status of nvSRAM when LOW. After each Hardware  
and Software STORE operation HSB is driven HIGH for a short time (tHHHD) with standard output high  
current and then a weak internal pull-up resistor keeps this pin HIGH (external pull-up resistor  
connection optional).  
Input: Hardware STORE implemented by pulling this pin LOW externally.  
VCAP  
Power supply AutoStore capacitor. Supplies power to the nvSRAM during power loss to STORE data from the SRAM  
to nonvolatile elements. If AutoStore is not needed, this pin must be left as No Connect. It must never  
be connected to ground.  
[2]  
VRTCcap  
Power supply Capacitor backup for RTC: Left unconnected if VRTCbat is used.  
Power supply Battery backup for RTC: Left unconnected if VRTCcap is used.  
[2]  
VRTCbat  
Xout[2]  
Xin[2]  
Output  
Input  
Crystal output connection  
Crystal input connection  
INT/SQW[2]  
Output  
Interrupt output/calibration/square wave. Programmable to respond to the clock alarm, the watchdog  
timer, and the power monitor. Also programmable to either active HIGH (push or pull) or LOW (open  
drain). In calibration mode, a 512 Hz square wave is driven out. In the square wave mode, you may  
select a frequency of 1 Hz, 512 Hz, 4,096 Hz, or 32,768 Hz to be used as a continuous output.  
NC  
VSS  
VCC  
No connect No connect. This pin is not connected to the die.  
Power supply Ground  
Power supply Power supply  
Note  
2. Left unconnected if RTC feature is not used.  
Document Number: 001-68249 Rev. *H  
Page 3 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
SRAM Read  
Device Operation  
A read cycle is performed at the SPI bus speed. The data is read  
out with zero cycle delay after the READ instruction is executed.  
READ instruction can be used upto 40 MHz clock speed. The  
READ instruction is issued through the SI pin of the nvSRAM and  
consists of the READ opcode and two bytes of address. The data  
is read out on the SO pin.  
CY14X064PA is a 64-Kbit serial (SPI) nvSRAM memory with  
integrated RTC and SPI interface. All the reads and writes to  
nvSRAM happen to the SRAM, which gives nvSRAM the unique  
capability to handle infinite writes to the memory. The data in  
SRAM is secured by a STORE sequence that transfers the data  
in parallel to the nonvolatile QuantumTrap cells. A small  
capacitor (VCAP) is used to AutoStore the SRAM data in  
nonvolatile cells when power goes down providing power-down  
data security. The QuantumTrap nonvolatile elements built in the  
reliable SONOS technology make nvSRAM the ideal choice for  
secure data storage.  
Speed higher than 40 MHz (up to 104 MHz) requires  
FAST_READ instruction. The FAST_READ instruction is issued  
through the SI pin of the nvSRAM and consists of the  
FAST_READ opcode, two bytes of address, and one dummy  
byte. The data is read out on the SO pin.  
CY14X064PA enables burst mode reads to be performed  
through SPI. This enables reads on consecutive addresses  
without issuing a new READ instruction. When the last address  
in memory is reached in burst mode read, the address rolls over  
to 0x0000 and the device continues to read.  
In CY14X064PA, the 64-Kbit memory array is organized as 8 K  
words × 8 bits. The memory can be accessed through a standard  
SPI interface that enables very high clock speeds up to 40 MHz  
with zero cycle delay read and write cycles. This nvSRAM chip  
also supports 104 MHz SPI access speed with a special  
instruction for read operation. CY14X064PA supports SPI  
modes 0 and 3 (CPOL, CPHA = 0, 0 and 1, 1) and operates as  
SPI slave. The device is enabled using the Chip Select (CS) pin  
and accessed through Serial Input (SI), Serial Output (SO), and  
Serial Clock (SCK) pins.  
The SPI read cycle sequence is defined in the Memory Access  
section of SPI Protocol Description.  
STORE Operation  
STORE operation transfers the data from the SRAM to the  
nonvolatile QuantumTrap cells. The CY14X064PA STOREs data  
to the nonvolatile cells using one of the three STORE operations:  
AutoStore, activated on device power-down; Software STORE,  
activated by a STORE instruction; and Hardware STORE,  
activated by the HSB. During the STORE cycle, an erase of the  
previous nonvolatile data is first performed, followed by a  
program of the nonvolatile elements. After a STORE cycle is  
initiated, read/write to CY14X064PA is inhibited until the cycle is  
completed.  
CY14X064PA provides the feature for hardware and software  
write protection through the WP pin and WRDI instruction.  
CY14X064PA also provides mechanisms for block write  
protection (1/4, 1/2, or full array) using BP0 and BP1 pins in the  
Status Register. Further, the HOLD pin is used to suspend any  
serial communication without resetting the serial sequence.  
CY14X064PA uses the standard SPI opcodes for memory  
access. In addition to the general SPI instructions for read and  
write, CY14X064PA provides four special instructions that allow  
access to four nvSRAM specific functions: STORE, RECALL,  
AutoStore Disable (ASDISB), and AutoStore Enable (ASENB).  
The HSB signal or the RDY bit in the Status Register can be  
monitored by the system to detect if a STORE or Software  
RECALL cycle is in progress. The busy status of nvSRAM is  
indicated by HSB being pulled LOW or RDY bit being set to ‘1’.  
To avoid unnecessary nonvolatile STOREs, AutoStore and  
Hardware STORE operations are ignored unless at least one  
write operation has taken place since the most recent STORE or  
RECALL cycle. However, software initiated STORE cycles are  
performed regardless of whether a write operation has taken  
place.  
The major benefit of nvSRAM over serial EEPROMs is that all  
reads and writes to nvSRAM are performed at the speed of SPI  
bus with zero cycle delay. Therefore, no wait time is required  
after any of the memory accesses. The STORE and RECALL  
operations need finite time to complete and all memory accesses  
are inhibited during this time. While a STORE or RECALL  
operation is in progress, the busy status of the device is indicated  
by the Hardware STORE Busy (HSB) pin and also reflected on  
the RDY bit of the Status Register.  
AutoStore Operation  
SRAM Write  
The AutoStore operation is a unique feature of nvSRAM which  
automatically stores the SRAM data to QuantumTrap cells  
during power-down. This STORE makes use of an external  
capacitor (VCAP) and enables the device to safely STORE the  
data in the nonvolatile memory when power goes down.  
All writes to nvSRAM are carried out on the SRAM and do not  
use up any endurance cycles of the nonvolatile memory. This  
allows you to perform infinite write operations. A write cycle is  
performed through the WRITE instruction. The WRITE  
instruction is issued through the SI pin of the nvSRAM and  
consists of the WRITE opcode, two bytes of address, and one  
byte of data. Write to nvSRAM is done at SPI bus speed with zero  
cycle delay.  
During normal operation, the device draws current from VCC to  
charge the capacitor connected to the VCAP pin. When the  
voltage on the VCC pin drops below VSWITCH during power-down,  
the device inhibits all memory accesses to nvSRAM and  
automatically performs a conditional STORE operation using the  
charge from the VCAP capacitor. The AutoStore operation is not  
initiated if no write cycle has been performed since last RECALL.  
CY14X064PA allows burst mode writes to be performed through  
SPI. This enables write operations on consecutive addresses  
without issuing a new WRITE instruction. When the last address  
in memory is reached in burst mode, the address rolls over to  
0x0000 and the device continues to write.  
Note If a capacitor is not connected to VCAP pin, AutoStore must  
be disabled by issuing the AutoStore Disable instruction  
(AutoStore Disable (ASDISB) Instruction on page 17). If  
AutoStore is enabled without a capacitor on the VCAP pin, the  
device attempts an AutoStore operation without sufficient charge  
The SPI write cycle sequence is defined in the Memory Access  
section of SPI Protocol Description.  
Document Number: 001-68249 Rev. *H  
Page 4 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
to complete the Store. This will corrupt the data stored in  
nvSRAM, Status Register as well as the serial number and it will  
unlock the SNL bit. To resume normal functionality, the WRSR  
instruction must be issued to update the nonvolatile bits BP0,  
BP1, and WPEN in the Status Register.  
Note For successful last data byte STORE, a hardware STORE  
should be initiated at least one clock cycle after the last data bit  
D0 is received.  
Upon completion of the STORE operation, the nvSRAM memory  
access is inhibited for tLZHSB time after HSB pin returns HIGH.  
The HSB pin must be left unconnected if not used.  
Figure 2 shows the proper connection of the storage capacitor  
(VCAP  
) for AutoStore operation. Refer to DC Electrical  
RECALL Operation  
Characteristics on page 32 for the size of the VCAP  
.
A RECALL operation transfers the data stored in the nonvolatile  
QuantumTrap elements to the SRAM. In CY14X064PA, a  
RECALL may be initiated in two ways: Hardware RECALL,  
initiated on power-up and Software RECALL, initiated by a SPI  
RECALL instruction.  
Figure 2. AutoStore Mode  
VCC  
0.1uF  
Internally, RECALL is a two step procedure. First, the SRAM data  
is cleared. Next, the nonvolatile information is transferred into the  
SRAM cells. All memory accesses are inhibited while a RECALL  
cycle is in progress. The RECALL operation does not alter the  
data in the nonvolatile elements.  
VCC  
CS  
Hardware RECALL (Power Up)  
VCAP  
During power-up, when VCC crosses VSWITCH, an automatic  
RECALL sequence is initiated, which transfers the content of  
nonvolatile memory on to the SRAM. The data would previously  
have been stored on the nonvolatile memory through a STORE  
sequence.  
VCAP  
VSS  
A Power Up RECALL cycle takes tFA time to complete and the  
memory access is disabled during this time. HSB pin is used to  
detect the Ready status of the device.  
Software STORE Operation  
Software STORE allows the user to trigger a STORE operation  
through a special SPI instruction. STORE operation is initiated  
by executing STORE instruction regardless of whether or not a  
write has been performed since the last NV operation.  
Software RECALL  
Software RECALL allows you to initiate a RECALL operation to  
restore the content of nonvolatile memory on to the SRAM. In  
CY14X064PA, this can be done by issuing a RECALL instruction  
in SPI.  
A STORE cycle takes tSTORE time to complete, during which all  
the memory accesses to nvSRAM are inhibited. The RDY bit of  
the Status Register or the HSB pin may be polled to find the  
Ready/Busy status of the nvSRAM. After the tSTORE cycle time  
is completed, the SRAM is activated again for read and write  
operations.  
A Software RECALL takes tRECALL time to complete during  
which all memory accesses to nvSRAM are inhibited. The  
controller must provide sufficient delay for the RECALL operation  
to complete before issuing any memory access instructions.  
Disabling and Enabling AutoStore  
Hardware STORE and HSB pin Operation  
If the application does not require the AutoStore feature, it can  
be disabled in CY14X064PA by using the ASDISB instruction. If  
this is done, the nvSRAM does not perform a STORE operation  
at power-down.  
The HSB pin in CY14X064PA is used to control and  
acknowledge STORE operations. If no STORE/RECALL is in  
progress, this pin can be used to request a Hardware STORE  
cycle. When the HSB pin is driven LOW, the CY14X064PA  
conditionally initiates a STORE operation after tDELAY duration.  
A STORE cycle starts only if a write to the SRAM has been  
performed since the last STORE or RECALL cycle. Reads and  
Writes to the memory are inhibited for tSTORE duration or as long  
as HSB pin is LOW. The HSB pin also acts as an open drain  
driver (internal 100 kweak pull-up resistor) that is internally  
driven LOW to indicate a busy condition when the STORE  
(initiated by any means) is in progress.  
AutoStore can be re enabled by using the ASENB instruction.  
However, these operations are not nonvolatile and if you need  
this setting to survive the power cycle, a STORE operation must  
be performed following AutoStore Disable or Enable operation.  
Note CY14X064PA comes from the factory with AutoStore  
Enabled and 0x00 written in all cells. If AutoStore is disabled and  
VCAP is not required, then the VCAP pin must be left open. The  
VCAP pin must never be connected to ground. The Power Up  
RECALL operation cannot be disabled in any case.  
Note After each Hardware and Software STORE operation, HSB  
is driven HIGH for a short time (tHHHD) with standard output high  
current and then remains HIGH by an internal 100 kpull-up  
resistor.  
Document Number: 001-68249 Rev. *H  
Page 5 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Serial Clock (SCK)  
Serial Peripheral Interface  
Serial clock is generated by the SPI master and the  
communication is synchronized with this clock after CS goes  
LOW.  
SPI Overview  
The SPI is a four-pin interface with Chip Select (CS), Serial Input  
(SI), Serial Output (SO), and Serial Clock (SCK) pins.  
CY14X064PA provides serial access to nvSRAM through SPI  
interface. The SPI bus on CY14X064PA can run at speeds up to  
104 MHz except RDRTC and READ instruction.  
CY14X064PA allows SPI modes  
0
and  
3
for data  
communication. In both these modes, the inputs are latched by  
the slave device on the rising edge of SCK and outputs are  
issued on the falling edge. Therefore, the first rising edge of SCK  
signifies the arrival of the first bit (MSB) of SPI instruction on the  
SI pin. Further, all data inputs and outputs are synchronized with  
SCK.  
The SPI is a synchronous serial interface which uses clock and  
data pins for memory access and supports multiple devices on  
the data bus. A device on SPI bus is activated using the CS pin.  
The relationship between chip select, clock, and data is dictated  
by the SPI mode. CY14X064PA supports SPI modes 0 and 3. In  
both these modes, data is clocked into the nvSRAM on the rising  
edge of SCK starting from the first rising edge after CS goes  
active.  
Data Transmission SI/SO  
SPI data bus consists of two lines, SI and SO, for serial data  
communication. The SI is also referred to as Master Out Slave  
In (MOSI) and SO is referred to as Master In Slave Out (MISO).  
The master issues instructions to the slave through the SI pin,  
while the slave responds through the SO pin. Multiple slave  
devices may share the SI and SO lines as described earlier.  
The SPI protocol is controlled by opcodes. These opcodes  
specify the commands from the bus master to the slave device.  
After CS is activated the first byte transferred from the bus  
master is the opcode. Following the opcode, any addresses and  
data are then transferred. The CS must go inactive after an  
operation is complete and before a new opcode can be issued.  
CY14X064PA has two separate pins for SI and SO, which can  
be connected with the master as shown in Figure 3 on page 7.  
Most Significant Bit (MSB)  
The commonly used terms used in SPI protocol are given below:  
The SPI protocol requires that the first bit to be transmitted is the  
Most Significant Bit (MSB). This is valid for both address and  
data transmission.  
SPI Master  
The SPI master device controls the operations on a SPI bus. A  
SPI bus may have only one master with one or more slave  
devices. All the slaves share the same SPI bus lines and the  
master may select any of the slave devices using the CS pin. All  
the operations must be initiated by the master activating a slave  
device by pulling the CS pin of the slave LOW. The master also  
generates the SCK and all the data transmission on SI and SO  
lines are synchronized with this clock.  
The 64-Kbit serial nvSRAM requires a 2-byte address for any  
read or write operation. However, since the address is only  
13 bits, it implies that the first three bits which are fed in are  
ignored by the device. Although these three bits are ‘don’t care’,  
Cypress recommends that these bits are treated as 0s to enable  
seamless transition to higher memory densities.  
Serial Opcode  
SPI Slave  
After the slave device is selected with CS going LOW, the first  
byte received is treated as the opcode for the intended operation.  
The SPI slave device is activated by the master through the Chip  
Select line. A slave device gets the SCK as an input from the SPI  
master and all the communication is synchronized with this  
clock. SPI slave never initiates a communication on the SPI bus  
and acts on the instruction from the master.  
CY14X064PA uses the standard opcodes for memory accesses.  
In addition to the memory accesses, CY14X064PA provides  
additional opcodes for the nvSRAM specific functions: STORE,  
RECALL, AutoStore Enable, and AutoStore Disable. Refer to  
Table 1 on page 9 for details on opcodes.  
CY14X064PA operates as a slave device and may share the SPI  
bus with multiple CY14X064PA devices or other SPI devices.  
Invalid Opcode  
Chip Select (CS)  
If an invalid opcode is received, the opcode is ignored and the  
device ignores any additional serial data on the SI pin until the  
next falling edge of CS and the SO pin remains tri-stated.  
For selecting any slave device, the master needs to pull down  
the corresponding CS pin. Any instruction can be issued to a  
slave device only while the CS pin is LOW.  
Status Register  
The CY14X064PA is selected when the CS pin is LOW. When  
the device is not selected, data through the SI pin is ignored and  
the serial output pin (SO) remains in a high-impedance state.  
CY14X064PA has an 8-bit Status Register. The bits in the Status  
Register are used to configure the SPI bus. These bits are  
described in the Table 3 on page 10.  
Note A new instruction must begin with the falling edge of CS.  
Therefore, only one opcode can be issued for each active Chip  
Select cycle.  
Document Number: 001-68249 Rev. *H  
Page 6 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Figure 3. System Configuration Using SPI nvSRAM  
S C K  
M O SI  
M IS O  
SC K  
S I  
S O  
SC K  
SI  
S O  
uC o ntroller  
CY14X064PA  
CY14X064PA  
C S  
H O LD  
C S  
H O LD  
C S 1  
H O LD 1  
C S 2  
H O LD 2  
The two SPI modes are shown in Figure 4 and Figure 5. The  
status of clock when the bus master is in standby mode and not  
transferring data is:  
SPI Modes  
CY14X064PA device may be driven by a microcontroller with its  
SPI peripheral running in either of these two modes:  
SCK remains at 0 for Mode 0  
SCK remains at 1 for Mode 3  
SPI Mode 0 (CPOL=0, CPHA=0)  
SPI Mode 3 (CPOL=1, CPHA=1)  
CPOL and CPHA bits must be set in the SPI controller for the  
either Mode 0 or Mode 3. CY14X064PA detects the SPI mode  
from the status of SCK pin when device is selected by bringing  
the CS pin LOW. If SCK pin is LOW when the device is selected,  
SPI Mode 0 is assumed and if SCK pin is HIGH, CY14X064PA  
works in SPI Mode 3.  
For both these modes, the input data is latched in on the rising  
edge of SCK starting from the first rising edge after CS goes  
active. If the clock starts from a high state (in mode 3), the first  
rising edge after the clock toggles is considered. The output data  
is available on the falling edge of SCK.  
Figure 5. SPI Mode 3  
Figure 4. SPI Mode 0  
CS  
CS  
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
SCK  
SI  
SCK  
SI  
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
MSB  
LSB  
MSB  
LSB  
Document Number: 001-68249 Rev. *H  
Page 7 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Power Down  
SPI Operating Features  
At power-down (continuous decay of VCC), when VCC drops from  
the normal operating voltage and below the VSWITCH threshold  
voltage, the device stops responding to any instruction sent to it.  
If a write cycle is in progress and the last data bit D0 has been  
received when the power goes down, it is allowed tDELAY time to  
complete the write. After this, all memory accesses are inhibited  
and a conditional AutoStore operation is performed (AutoStore is  
not performed if no writes have happened since the last RECALL  
cycle). This feature prevents inadvertent writes to nvSRAM from  
happening during power-down. However, to avoid the possibility  
of inadvertent writes during power-down, ensure that the device  
is deselected and is in standby power mode and the CS follows  
Power-Up  
Power-up is defined as the condition when the power supply is  
turned on and VCC crosses Vswitch voltage.  
As described earlier, at power-up nvSRAM performs a Power-Up  
RECALL operation for tFA duration during which, all memory  
accesses are disabled. The HSB pin can be probed to check the  
Ready/Busy status of nvSRAM after power-up.  
The following are the device status after power-up.  
Selected (Active power mode) if CS pin is LOW  
Deselected (Standby power mode) if CS pin is HIGH  
Not in the Hold condition  
the voltage applied on VCC  
.
Active Power and Standby Power Modes  
Status Register state:  
Write Enable (WEN) bit is reset to ‘0’.  
WPEN, BP1, BP0 unchanged from previous STORE  
operation.  
When CS is LOW, the device is selected and is in the active  
power mode. The device consumes ICC current, as specified in  
DC Electrical Characteristics on page 32. When CS is HIGH, the  
device is deselected and the device goes into the standby power  
mode after tSB time if a STORE or RECALL cycle is not in  
progress. If a STORE/RECALL cycle is in progress, the device  
goes into the standby power mode after the STORE/RECALL  
cycle is completed. In the standby power mode the current drawn  
The WPEN, BP1, and BP0 bits of the Status Register are nonvol-  
atile bits and remain unchanged from the previous STORE  
operation.  
by the device drops to ISB  
.
Document Number: 001-68249 Rev. *H  
Page 8 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
SPI Functional Description  
The CY14X064PA uses an 8-bit instruction register. Instructions and their operation codes are listed in Table 3. All instructions,  
addresses, and data are transferred with the MSB first and start with a HIGH to LOW CS transition. There are, in all, 21 SPI instructions  
that provide access to most of the functions in nvSRAM. Further, the WP, HOLD, and HSB pins provide additional functionality driven  
through hardware.  
Table 1. Instruction Set  
Instruction Category  
Instruction Name  
Opcode  
Operation  
Status Register Control Instructions  
RDSR  
0000 0101  
0000 1001  
0000 0001  
0000 0110  
0000 0100  
Read Status Register  
Status Register access  
FAST_RDSR  
Fast Status Register read - SPI clock > 40 MHz  
Write Status Register  
WRSR  
WREN  
WRDI  
Set Write Enable latch  
Write protection and block  
protection  
Reset Write Enable latch  
SRAM Read/Write Instructions  
READ  
0000 0011  
0000 1011  
0000 0010  
Read data from memory array  
Fast read - SPI clock > 40 MHz  
Write data to memory array  
Memory access  
FAST_READ  
WRITE  
RTC Read/Write Instructions  
RTC access  
RDRTC  
0001 0011  
0001 1101  
0001 0010  
Read RTC registers  
FAST_RDRTC  
WRTC  
Fast RTC register read - SPI clock > 25 MHz  
Write RTC registers  
Special NV Instructions  
STORE  
RECALL  
ASENB  
ASDISB  
0011 1100  
0110 0000  
0101 1001  
0001 1001  
Software STORE  
Software RECALL  
AutoStore enable  
AutoStore disable  
nvSRAM special functions  
Special Instructions  
Sleep  
SLEEP  
1011 1001  
1100 0010  
1100 0011  
1100 1001  
1001 1111  
1001 1001  
Sleep mode enable  
WRSN  
Write serial number  
Serial number  
RDSN  
Read serial number  
FAST_RDSN  
RDID  
Fast serial number read - SPI clock > 40 MHz  
Read manufacturer JEDEC ID and product ID  
Device ID read  
Reserved  
FAST_RDID  
Fast manufacturer JEDEC ID and product ID Read - SPI  
clock > 40 MHz  
- Reserved -  
0001 1110  
The SPI instructions in CY14X064PA are divided based on their  
functionality in these types:  
Status Register control instructions:  
• Status Register access: RDSR, FAST_RDSR and WRSR  
instructions  
RTC Read/Write instructions  
• RTC access: RDRTC, FAST_RDRTC and WRTC  
instructions  
Special NV instructions  
• nvSRAM special instructions: STORE, RECALL, ASENB,  
and ASDISB  
• Write protection and block protection: WREN and WRDI  
instructions along with WP pin and WEN, BP0, and BP1  
bits  
Special instructions: SLEEP, WRSN, RDSN, FAST_RDSN,  
RDID, FAST_RDID  
SRAM Read/Write instructions  
• Memory access: READ, FAST_READ, and WRITE instruc-  
tions  
Document Number: 001-68249 Rev. *H  
Page 9 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
and RDY bits. The default value shipped from the factory for  
WEN, BP0, BP1, bits 4 -5, SNL and WPEN is ‘0’.  
Status Register  
The Status Register bits are listed in Table 2. The Status Register  
consists of a Ready bit (RDY) and data protection bits BP1, BP0,  
WEN, and WPEN. The RDY bit can be polled to check the  
Ready/Busy status while a nvSRAM STORE or Software  
RECALL cycle is in progress. The Status Register can be  
modified by WRSR instruction and read by RDSR or  
FAST_RDSR instruction. However, only the WPEN, BP1, and  
BP0 bits of the Status Register can be modified by using the  
WRSR instruction. The WRSR instruction has no effect on WEN  
SNL (bit 6) of the Status Register is used to lock the serial  
number written using the WRSN instruction. The serial number  
can be written using the WRSN instruction multiple times while  
this bit is still '0'. When set to '1', this bit prevents any modification  
to the serial number. This bit is factory programmed to '0' and can  
only be written to once. After this bit is set to '1', it can never be  
cleared to '0'.  
Table 2. Status Register Format  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
WPEN (0)  
SNL (0)  
X (0)  
X (0)  
BP1 (0)  
BP0 (0)  
WEN (0)  
RDY  
Table 3. Status Register Bit Definition  
Bit  
Definition  
Description  
Bit 0 (RDY)  
Ready  
Read only bit indicates the ready status of device to perform a memory access. This bit is  
set to ‘1’ by the device while a STORE or Software RECALL cycle is in progress.  
Bit 1 (WEN) Write Enable  
WEN indicates if the device is write enabled. This bit defaults to 0 (disabled) on power-up.  
WEN = '1' --> Write enabled  
WEN = '0' --> Write disabled  
Bit 2 (BP0)  
Bit 3 (BP1)  
Bit 4-5  
Block Protect bit ‘0’  
Used for block protection. For details see Table 4 on page 12.  
Used for block protection. For details see Table 4 on page 12.  
These bits are non-writable and always return ‘0’ upon read.  
Set to '1' for locking serial number  
Block Protect bit ‘1’  
Don’t care  
Bit 6 (SNL)  
Serial Number Lock  
Bit 7(WPEN) Write Protect Enable bit Used for enabling the function of Write Protect Pin (WP). For details see Table 5 on page 12.  
This instruction is issued after the falling edge of CS using the  
opcode for RDSR followed by a dummy byte.  
Read Status Register (RDSR) Instruction  
The Read Status Register instruction provides access to the  
Status Register at SPI frequency up to 40 MHz. This instruction  
is used to probe the Write Enable status of the device or the  
Ready status of the device. RDY bit is set by the device to ‘1’  
whenever a STORE or Software RECALL cycle is in progress.  
The block protection and WPEN bits indicate the extent of  
protection employed.  
Write Status Register (WRSR) Instruction  
The WRSR instruction enables the user to write to the Status  
Register. However, this instruction cannot be used to modify bit  
0 (RDY), bit 1 (WEN) and bits 4-5. The BP0 and BP1 bits can be  
used to select one of four levels of block protection. Further,  
WPEN bit must be set to ‘1’ to enable the use of Write Protect  
(WP) pin.  
This instruction is issued after the falling edge of CS using the  
opcode for RDSR.  
WRSR instruction is a write instruction and needs writes to be  
enabled (WEN bit set to ‘1’) using the WREN instruction before  
it is issued. The instruction is issued after the falling edge of CS  
using the opcode for WRSR followed by eight bits of data to be  
stored in the Status Register. WRSR instruction can be used to  
modify only bits 2, 3, 6 and 7 of the Status Register.  
Fast Read Status Register (FAST_RDSR) Instruction  
The FAST_RDSR instruction allows you to read the Status  
Register at SPI frequency above 40 MHz and up to 104 MHz  
(max).This instruction is used to probe the Write Enable status  
of the device or the Ready status of the device. RDY bit is set by  
the device to ‘1’ whenever a STORE or Software RECALL cycle  
is in progress. The block protection and WPEN bits indicate the  
extent of protection employed.  
Note In CY14X064PA, the values written to Status Register are  
saved to nonvolatile memory only after a STORE operation. If  
AutoStore is disabled, any modifications to the Status Register  
must be secured by performing a Software STORE operation.  
Document Number: 001-68249 Rev. *H  
Page 10 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Figure 6. Read Status Register (RDSR) Instruction Timing  
CS  
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
SCK  
Op-Code  
SI  
0
0
0
0
0
1
0
1
HI-Z  
SO  
D4  
D2  
D7 D6 D5  
MSB  
D3  
D1 D0  
LSB  
Data  
Figure 7. Fast Read Status Register (FAST_RDSR) Instruction Timing  
CS  
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15  
Dummy Byte  
0
1
2
3
4
5
6
7
SCK  
Op-Code  
SI  
X
X
X
X
X
0
0
0
0
1
0
0
1
X
X
X
HI-Z  
SO  
D4  
D2  
D7 D6 D5  
MSB  
D3  
D1 D0  
LSB  
Data  
Figure 8. Write Status Register (WRSR) Instruction Timing  
CS  
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
SCK  
Data in  
Opcode  
D2  
D3  
X
SI  
1
D7  
X
X
0
0
0
0
0
0
0
X
X
MSB  
LSB  
HI-Z  
SO  
instruction must therefore be preceded by a Write Enable  
instruction. If the device is not write enabled (WEN = ‘0’), it  
ignores the write instructions and returns to the standby state  
when CS is brought HIGH. A new CS falling edge is required to  
re-initiate serial communication. The instruction is issued  
following the falling edge of CS. When this instruction is used,  
the WEN bit of Status Register is set to ‘1’. WEN bit defaults to  
‘0’ on power-up.  
Write Protection and Block Protection  
CY14X064PA provides features for both software and hardware  
write protection using WRDI instruction and WP. Additionally, this  
device also provides block protection mechanism through BP0  
and BP1 pins of the Status Register.  
The write enable and disable status of the device is indicated by  
WEN bit of the Status Register. The write instructions (WRSR,  
WRITE, WRTC and WRSN) and nvSRAM special instruction  
(STORE, RECALL, ASENB, ASDISB) need the write to be  
enabled (WEN bit = ‘1’) before they can be issued.  
Note After completion of a write instruction (WRSR, WRITE,  
WRTC or WRSN) or nvSRAM special instruction (STORE,  
RECALL, ASENB, ASDISB) instruction, WEN bit is cleared to ‘0’.  
This is done to provide protection from any inadvertent writes.  
Therefore, WREN instruction needs to be used before a new  
write instruction is issued.  
Write Enable (WREN) Instruction  
On power-up, the device is always in the write disable state. The  
following WRITE, WRSR, WRTC, WRSN or nvSRAM special  
Document Number: 001-68249 Rev. *H  
Page 11 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
WP pin can be used along with WPEN and Block Protect bits  
(BP1 and BP0) of the Status Register to inhibit writes to memory.  
When WP pin is LOW and WPEN is set to ‘1’, any modifications  
to Status Register are disabled. Therefore, the memory is  
protected by setting the BP0 and BP1 bits and the WP pin inhibits  
any modification of the Status Register bits, providing hardware  
write protection.  
Figure 9. WREN Instruction  
CS  
0
1
2
3
4
5
6
7
SCK  
SI  
Note WP going LOW when CS is still LOW has no effect on any  
of the ongoing write operations to the Status Register.  
0
0
0
0
0
1
1
0
Table 5 summarizes all the protection features provided in the  
CY14X064PA.  
HI-Z  
Table 5. Write Protection Operation  
SO  
Protected Unprotected Status  
WPEN WP  
WEN  
Write Disable (WRDI) Instruction  
Blocks  
Blocks  
Protected  
Writable  
Writable  
Writable  
Register  
Protected  
Writable  
Protected  
Writable  
Write Disable instruction disables the write by clearing the WEN  
bit to ‘0’ to protect the device against inadvertent writes. This  
instruction is issued following the falling edge of CS followed by  
opcode for WRDI instruction. The WEN bit is cleared on the  
rising edge of CS following a WRDI instruction.  
X
0
1
1
X
0
1
1
1
Protected  
Protected  
Protected  
Protected  
X
LOW  
HIGH  
Figure 10. WRDI Instruction  
Memory Access  
CS  
All memory accesses are done using the READ and WRITE  
instructions. These instructions cannot be used while a STORE  
or RECALL cycle is in progress. A STORE cycle in progress is  
indicated by the RDY bit of the Status Register and the HSB pin.  
0
1
2
3
4
5
6
7
SCK  
SI  
0
0
0
0
0
1
0
0
Read Sequence (READ) Instruction  
The read operations on this device are performed by giving the  
instruction on the SI pin and reading the output on SO pin. The  
following sequence needs to be followed for a read operation:  
After the CS line is pulled LOW to select a device, the read  
opcode is transmitted through the SI line followed by two bytes  
of address (A12–A0). The most significant address bits  
(A15–A13) are don’t cares. After the last address bit is  
transmitted on the SI pin, the data (D7–D0) at the specific  
address is shifted out on the SO line on the falling edge of SCK  
starting with D7. Any other data on SI line after the last address  
bit is ignored.  
HI-Z  
SO  
Block Protection  
Block protection is provided using the BP0 and BP1 pins of the  
Status Register. These bits can be set using WRSR instruction  
and probed using the RDSR instruction. The nvSRAM is divided  
into four array segments. One-quarter, one-half, or all of the  
memory segments can be protected. Any data within the  
protected segment is read only. Table 4 shows the function of  
Block Protect bits.  
CY14X064PA allows reads to be performed in bursts through  
SPI which can be used to read consecutive addresses without  
issuing a new READ instruction. If only one byte is to be read,  
the CS line must be driven HIGH after one byte of data comes  
out. However, the read sequence may be continued by holding  
the CS line LOW and the address is automatically incremented  
and data continues to shift out on SO pin. When the last data  
memory address (0x1FFF) is reached, the address rolls over to  
0x0000 and the device continues to read.  
Table 4. Block Write Protect Bits  
Status Register Bits  
Level  
Array Addresses Protected  
BP1  
BP0  
0
0
0
1
1
0
1
0
1
None  
1 (1/4)  
2 (1/2)  
3 (All)  
0x1800-0x1FFF  
0x1000-0x1FFF  
0x0000-0x1FFF  
Fast Read Sequence (FAST_READ) Instruction  
Hardware Write Protection (WP Pin)  
The FAST_READ instruction allows you to read memory at SPI  
frequency above 40 MHz and up to 104 MHz (Max). The host  
system must first select the device by driving CS LOW, the  
FAST_READ instruction is then written to SI, followed by 2  
address byte (A12–A0) and then a dummy byte. The most  
significant address bits (A15–A13) are don’t cares.  
The write protect pin (WP) is used to provide hardware write  
protection. WP pin enables all normal read and write operations  
when held HIGH. When the WP pin is brought LOW and WPEN  
bit is ‘1’, all write operations to the Status Register are inhibited.  
The hardware write protection function is blocked when the  
WPEN bit is ‘0’. This allows you to install the device in a system  
with the WP pin tied to ground, and still write to the Status  
Register.  
From the subsequent falling edge of the SCK, the data of the  
specific address is shifted out serially on the SO line starting with  
MSB. The first byte specified can be at any location. The device  
Document Number: 001-68249 Rev. *H  
Page 12 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
automatically increments to the next higher address after each  
byte of data is output. The entire memory array can therefore be  
read with a single FAST_READ instruction. When the highest  
address in the memory array is reached, address counter rolls  
over to start address 0x0000 and thus allowing the read  
sequence to continue indefinitely. The FAST_READ instruction  
is terminated by driving CS HIGH at any time during data output.  
CY14X064PA enables writes to be performed in bursts through  
SPI which can be used to write consecutive addresses without  
issuing a new WRITE instruction. If only one byte is to be written,  
the CS line must be driven HIGH after the D0 (LSB of data) is  
transmitted. However, if more bytes are to be written, CS line  
must be held LOW and address is incremented automatically.  
The following bytes on the SI line are treated as data bytes and  
written in the successive addresses. When the last data memory  
address (0x1FFF) is reached, the address rolls over to 0x0000  
and the device continues to write. The WEN bit is reset to ‘0’ on  
completion of a WRITE sequence.  
Note FAST_READ instruction operates up to maximum of  
104 MHz SPI frequency.  
Write Sequence (WRITE) Instruction  
Note When a burst write reaches a protected block address, it  
continues the address increment into the protected space but  
does not write any data to the protected memory. If the address  
roll over takes the burst write to unprotected space, it resumes  
writes. The same operation is true if a burst write is initiated  
within a write protected block.  
The write operations on this device are performed through the SI  
pin. To perform a write operation, if the device is write disabled,  
then the device must first be write enabled through the WREN  
instruction. When the writes are enabled (WEN = ‘1’), WRITE  
instruction is issued after the falling edge of CS. A WRITE  
instruction constitutes transmitting the WRITE opcode on SI line  
followed by two bytes of address (A12–A0) and the data (D7–D0)  
which is to be written. The most significant address bits  
(A15–A13) are don’t cares.  
Figure 11. Read Instruction Timing  
CS  
0
1
0
1
2
3
4
5
6
7
2
3
4
5
6
7
12 13 14 15  
0
1
2
3
4
5
6
7
SCK  
13-bit Address  
A11 A10 A9 A8  
Op-Code  
SI  
0
0
0
0
0
0
1
1
A3  
A2 A1 A0  
X
X
X
A12  
MSB  
LSB  
HI-Z  
SO  
D7 D6 D5 D4 D3  
D2  
D1  
D0  
MSB  
LSB  
Data  
Figure 12. Burst Mode Read Instruction Timing  
CS  
12 13 14 15  
0
1
0
1
2
3
4
5
6
7
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
0
1
2
3
4
5
6
7
7
SCK  
SI  
Op-Code  
13-bit Address  
A8  
1
1
X
X
X
A12 A11 A10 A9  
A3 A2 A1 A0  
0
0
0
0
0
0
MSB  
LSB  
Data Byte N  
Data Byte 1  
HI-Z  
SO  
D7 D6 D5 D4  
D0  
D3 D2 D1 D0  
D3 D2  
D7 D0 D7 D6 D5 D4  
D1  
MSB  
MSB  
LSB  
LSB  
Document Number: 001-68249 Rev. *H  
Page 13 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Figure 13. Fast Read Instruction Timing  
CS  
0
1
2
3
4
5
6
7
0
1
0
1
2
3
4
5
6
7
2
3
4
5
6
7
12 13 14 15 16 17 18 19 20 21 22 23  
SCK  
Op-Code  
Dummy Byte  
13-bit Address  
A12  
X
X
X
X
X
X
SI  
A11 A10 A9 A8  
X
X
0
0
0
0
1
0
1
1
A3  
A2 A1 A0  
X
X
X
MSB  
LSB  
HI-Z  
SO  
D7 D6 D5 D4 D3  
D0  
D2  
D1  
Data  
MSB  
LSB  
Figure 14. Write Instruction Timing  
CS  
0
1
0
1
2
3
4
5
7
2
3
4
5
6
7
12 13 14 15  
0
1
2
3
4
5
6
7
6
SCK  
Op-Code  
13-bit Address  
D4  
D2  
SI  
D7 D6 D5  
D3  
D1 D0  
0
0
0
0
0
0
1
0
A8  
A3  
A2 A1 A0  
X
X
X
A12 A11 A10 A9  
MSB  
LSBMSB  
LSB  
Data  
HI-Z  
SO  
Figure 15. Burst Mode Write Instruction Timing  
CS  
14 15  
12 13  
0
1
0
1
2
3
4
5
6
7
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
0
1
2
3
4
5
6
7
7
SCK  
Data Byte N  
Data Byte 1  
Op-Code  
13-bit Address  
A8  
D7 D6 D5 D4  
MSB  
D7 D0 D7 D6 D5 D4  
D3 D2  
D3 D2  
D1 D0  
1
0
X
X
X
A12 A11A10 A9  
A3 A2 A1 A0  
LSB  
D1 D0  
0
0
0
0
0
0
SI  
MSB  
LSB  
HI-Z  
SO  
Document Number: 001-68249 Rev. *H  
Page 14 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
The ‘R’ bit in RTC flags register must be set to ‘1’ before reading  
RTC time keeping registers to avoid reading transitional data.  
Modifying the RTC flag registers requires a Write RTC cycle. The  
R bit must be cleared to '0' after completion of the read operation.  
RTC Access  
CY14X064PA uses 16 registers for RTC. These registers can be  
read out or written to by accessing all 16 registers in burst mode  
or accessing each register, one at a time. The RDRTC,  
FAST_RDRTC, and WRTC instructions are used to access the  
RTC.  
The easiest way to read RTC registers is to perform RDRTC in  
burst mode. The read may start from the first RTC register (0x00)  
and the CS must be held LOW to allow the data from all 16 RTC  
registers to be transmitted through the SO pin.  
All the RTC registers can be read in burst mode by issuing the  
RDRTC and FAST_RDRTC instruction and reading all 16 bytes  
without bringing the CS pin HIGH. The ‘R’ bit must be set while  
reading the RTC timekeeping registers to ensure that transitional  
values of time are not read.  
Note RDRTC instruction operates at a maximum clock  
frequency of 25 MHz. The opcode cycles, address cycles and  
data out cycles need to run at 25 MHz for the instruction to work  
properly.  
Writes to the RTC register are performed using the WRTC  
instruction. Writing RTC timekeeping registers and control  
registers, except for the flags register needs the ‘W’ bit of the  
flags register to be set to ‘1’. The internal counters are updated  
with the new date and time setting when the ‘W’ bit is cleared to  
‘0’. All the RTC registers can also be written in burst mode using  
the WRTC instruction.  
Fast Read Sequence (FAST_RDRTC) Instruction  
The FAST_RDRTC instruction allows you to read memory at a  
SPI frequency above 25 MHz and up to 104 MHz (Max). The host  
system must first select the device by driving CS LOW, the  
FAST_READ instruction is then written to SI, followed by 8 bit  
address and a dummy byte.  
From the subsequent falling edge of the SCK, the data of the  
specific address is shifted out serially on the SO line starting with  
MSB. The first byte specified can be at any location. The device  
automatically increments to the next higher address after each  
byte of data is output. The entire memory array can therefore be  
read with a single FAST_RDRTC instruction. When the highest  
address (0x0F) in the memory array is reached, the address  
counter rolls over to start address 0x00 and thus allowing the  
read sequence to continue indefinitely. The FAST_RDRTC  
instruction is terminated by driving CS HIGH at any time during  
data output.  
READ RTC (RDRTC) Instruction  
Read RTC (RDRTC) instruction allows you to read the contents  
of RTC registers at SPI frequency upto 25 MHz. Reading the  
RTC registers through the SO pin requires the following  
sequence: After the CS line is pulled LOW to select a device, the  
RDRTC opcode is transmitted through the SI line followed by  
eight address bits for selecting the register. Any data on the SI  
line after the address bits is ignored. The data (D7-D0) at the  
specified address is then shifted out onto the SO line. RDRTC  
also allows burst mode read operation. When reading multiple  
bytes from RTC registers, the address rolls over to 0x00 after the  
last RTC register address (0x0F) is reached.  
Note FAST_READ instruction operates up to Max of 104 MHz  
SPI frequency.  
Figure 16. Read RTC (RDRTC) Instruction Timing  
CS  
0
1
0
1
2
3
4
5
6
7
2
4
5
6
7
0
1
2
3
4
5
6
7
3
SCK  
Op-Code  
1
0
0
0
SI  
0
0
1
1
0
0
0
0
A3  
A2 A1  
A0  
LSB  
MSB  
HI-Z  
SO  
D4 D3 D2  
Data  
D0  
D7 D6  
D1  
D5  
MSB  
LSB  
Document Number: 001-68249 Rev. *H  
Page 15 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Figure 17. Fast RTC Read (FAST_RDRTC) Instruction Timing  
CS  
0
1
0
1
2
3
4
5
6
7
2
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23  
Dummy Byte  
3
SCK  
Op-Code  
0
0
0
SI  
1
1
1
0
1
0
MSB  
0
0
0
A2 A1  
X
X
X
X
A3  
A0  
LSB  
X
X
X
X
HI-Z  
SO  
D4 D3 D2  
Data  
D0  
D7 D6  
MSB  
D1  
D5  
LSB  
bytes of data. WRTC allows burst mode write operation. When  
writing more than one registers in burst mode, the address rolls  
over to 0x00 after the last RTC address (0x0F) is reached.  
WRITE RTC (WRTC) Instruction  
WRITE RTC (WRTC) instruction allows you to modify the  
contents of RTC registers. The WRTC instruction requires the  
WEN bit to be set to '1' before it can be issued. If WEN bit is '0',  
a WREN instruction needs to be issued before using WRTC.  
Writing RTC registers requires the following sequence: After the  
CS line is pulled LOW to select a device, WRTC opcode is  
transmitted through the SI line followed by eight address bits  
identifying the register which is to be written to and one or more  
Note that writing to RTC timekeeping and control registers  
require the W bit to be set to '1'. The values in these RTC  
registers take effect only after the ‘W’ bit is cleared to '0'. Write  
Enable bit (WEN) is automatically cleared to ‘0’ after completion  
of the WRTC instruction.  
Figure 18. Write RTC (WRTC) Instruction Timing  
CS  
0
1
0
1
2
3
4
5
6
7
2
4
5
6
7
0
1
2
3
4
5
6
7
3
SCK  
Op-Code  
1
4-bit Address  
A0  
0
0
0
SI  
0
0
1
0
0
0
0
0
A3  
A2 A1  
D7 D6  
MSB  
D4  
D2 D1 D0  
LSB  
D5  
D3  
MSB  
LSB  
Data  
HI-Z  
SO  
Document Number: 001-68249 Rev. *H  
Page 16 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
AutoStore Enable (ASENB) Instruction  
nvSRAM Special Instructions  
The AutoStore Enable instruction enables the AutoStore on  
CY14X064PA. This setting is not nonvolatile and needs to be  
followed by a STORE sequence if this is desired to survive the  
power cycle.  
CY14X064PA provides four special instructions that allow  
access to the nvSRAM specific functions: STORE, RECALL,  
ASDISB, and ASENB. Table 6 lists these instructions.  
Table 6. nvSRAM Special Instructions  
To issue this instruction, the device must be write enabled  
(WEN = ‘1’). The instruction is performed by transmitting the  
ASENB opcode on the SI pin following the falling edge of CS.  
The WEN bit is cleared on the positive edge of CS following the  
ASENB instruction.  
Function Name  
STORE  
Opcode  
0011 1100  
0110 0000  
Operation  
Software STORE  
Software RECALL  
RECALL  
ASENB  
0101 1001 AutoStore Enable  
0001 1001 AutoStore Disable  
Figure 21. AutoStore Enable Operation  
ASDISB  
CS  
Software STORE (STORE) Instruction  
0
1
2
3
4
5
6
7
When a STORE instruction is executed, CY14X064PA performs  
a Software STORE operation. The STORE operation is  
performed regardless of whether or not a write has taken place  
since the last STORE or RECALL operation.  
SCK  
SI  
0
1
0
1
1
0
0
1
Figure 19. Software STORE Operation  
HI-Z  
SO  
CS  
AutoStore Disable (ASDISB) Instruction  
0
1
2
3
4
5
6
7
AutoStore is enabled by default in CY14X064PA. The AutoStore  
Disable instruction disables the AutoStore on CY14X064PA.  
This setting is not nonvolatile and needs to be followed by a  
STORE sequence if this is desired to survive the power cycle.  
SCK  
SI  
0
0
1
1
1
1
0
0
To issue this instruction, the device must be write enabled  
(WEN = ‘1’). The instruction is performed by transmitting the  
ASDISB opcode on the SI pin following the falling edge of CS.  
The WEN bit is cleared on the positive edge of CS following the  
ASDISB instruction.  
HI-Z  
SO  
To issue this instruction, the device must be write enabled (WEN  
bit = ‘1’).The instruction is performed by transmitting the STORE  
opcode on the SI pin following the falling edge of CS. The WEN  
bit is cleared on the positive edge of CS following the STORE  
instruction.  
Figure 22. AutoStore Disable Operation  
Software RECALL (RECALL) Instruction  
CS  
When  
performs  
a
RECALL instruction is executed, CY14X064PA  
Software RECALL operation. To issue this  
0
1
2
3
4
5
6
7
a
SCK  
SI  
instruction, the device must be write enabled (WEN = ‘1’).  
The instruction is performed by transmitting the RECALL opcode  
on the SI pin following the falling edge of CS. The WEN bit is  
cleared on the positive edge of CS following the RECALL  
instruction.  
0
0
0
1
1
0
0
1
HI-Z  
SO  
.
Figure 20. Software RECALL Operation  
Special Instructions  
CS  
SLEEP Instruction  
0
1
2
3
4
5
6
7
SLEEP instruction puts the nvSRAM in sleep mode. When the  
SLEEP instruction is issued, the nvSRAM takes tSS time to  
process the SLEEP request. Once the SLEEP command is  
successfully registered and processed, the nvSRAM toggles  
HSB LOW, performs a STORE operation to secure the data to  
nonvolatile memory and then enters into SLEEP mode. The  
device starts consuming IZZ current after tSLEEP time from the  
SCK  
SI  
0
1
1
0
0
0
0
0
HI-Z  
SO  
Document Number: 001-68249 Rev. *H  
Page 17 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
instance when SLEEP instruction is registered. The device is not  
accessible for normal operations after SLEEP instruction is  
issued. Once in sleep mode, the SCK and SI pins are ignored  
and SO will be Hi-Z but device continues to monitor the CS pin.  
Serial Number  
The serial number is an 8-byte programmable memory space  
provided to you to uniquely identify this device. It typically  
consists of a two byte Customer ID, followed by five bytes of  
unique serial number and one byte of CRC check. However,  
nvSRAM does not calculate the CRC and it is up to the system  
designer to utilize the eight byte memory space in whatever  
manner desired. The default value for eight byte locations are set  
to ‘0x00’.  
To wake the nvSRAM from the sleep mode, the device must be  
selected by toggling the CS pin from HIGH to LOW. The device  
wakes up and is accessible for normal operations after tWAKE  
duration after a falling edge of CS pin is detected.  
Note Whenever nvSRAM enters into sleep mode, it initiates  
nonvolatile STORE cycle which results in an endurance cycle per  
sleep command execution. A STORE cycle starts only if a write  
to the SRAM has been performed since the last STORE or  
RECALL cycle.  
WRSN (Serial Number Write) Instruction  
The serial number can be written using the WRSN instruction. To  
write serial number the write must be enabled using the WREN  
instruction. The WRSN instruction can be used in burst mode to  
write all the 8 bytes of serial number.  
Figure 23. Sleep Mode Entry  
The serial number is locked using the SNL bit of the Status  
Register. Once this bit is set to '1', no modification to the serial  
number is possible. After the SNL bit is set to '1', using the WRSN  
instruction has no effect on the serial number.  
t
SLEEP  
CS  
0
1
2
3
4
5
6
7
A STORE operation (AutoStore or Software STORE) is required  
to store the serial number in nonvolatile memory. If AutoStore is  
disabled, you must perform a Software STORE operation to  
secure and lock the serial number. If SNL bit is set to ‘1’ and is  
not stored (AutoStore disabled), the SNL bit and serial number  
defaults to ‘0’ at the next power cycle. If SNL bit is set to ‘1’ and  
is stored, the SNL bit can never be cleared to ‘0’. This instruction  
requires the WEN bit to be set before it can be executed. The  
WEN bit is reset to '0' after completion of this instruction.  
SCK  
SI  
1
0
1
1
1
0
0
1
HI-Z  
SO  
Figure 24. WRSN Instruction  
CS  
0
1
0
1
2
0
3
4
5
7
2
3
4
5
6
7
6
56 57 58 59 60 61 62 63  
SCK  
Byte - 1  
Byte - 8  
Op-Code  
D5  
D0  
D6  
D2 D1 D0  
LSB  
D4  
D4  
D3  
D6  
D3 D2 D1  
D7  
D5  
D7  
SI  
1
1
0
0
0
1
0
MSB  
8-Byte Serial Number  
HI-Z  
SO  
Document Number: 001-68249 Rev. *H  
Page 18 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
RDSN (Serial Number Read) Instruction  
The serial number is read using RDSN instruction at SPI frequency upto 40 MHz. A serial number read may be performed in burst  
mode to read all the eight bytes at once. After the last byte of serial number is read, the device does not loop back. RDSN instruction  
can be issued by shifting the op-code for RDSN in through the SI pin of nvSRAM after CS goes LOW. This is followed by nvSRAM  
shifting out the eight bytes of serial number through the SO pin.  
Figure 25. RDSN Instruction  
CS  
0
1
0
1
2
0
3
4
5
7
2
3
4
5
6
7
6
56 57 58 59 60 61 62 63  
SCK  
Op-Code  
SI  
1
1
0
0
0
1
1
Byte - 1  
Byte - 8  
HI-Z  
D5  
D0  
D6  
D2 D1 D0  
LSB  
SO  
D6  
D4  
D3  
D1  
D7  
D4  
D5 D3  
D2  
D7  
MSB  
8-Byte Serial Number  
FAST_RDSN (Fast Serial Number Read) Instruction  
The FAST_RDSN instruction is used to read serial number at SPI frequency above 40 MHz and up to 104 MHz (max). A serial number  
read may be performed in burst mode to read all the eight bytes at once. After the last byte of serial number is read, the device does  
not loop back. FAST_RDSN instruction can be issued by shifting the op-code for FAST_RDSN in through the SI pin of nvSRAM  
followed by dummy byte after CS goes LOW. This is followed by nvSRAM shifting out the eight bytes of serial number through the SO  
pin.  
Figure 26. FAST_RDSN Instruction  
CS  
0
1
0
1
2
0
3
4
5
7
2
3
4
5
6
7
6
8
9
10 11 12 13  
Dummy Byte  
15  
X
56 57 58 59 60 61 62 63  
14  
SCK  
Op-Code  
X
X
X
X
X
SI  
X
X
1
1
0
1
0
0
1
Byte - 1  
Byte - 8  
HI-Z  
D5  
D0  
D6  
D2 D1 D0  
LSB  
SO  
D6  
D4  
D3  
D1  
D7  
D4  
D5 D3  
D2  
D7  
MSB  
8-Byte Serial Number  
Document Number: 001-68249 Rev. *H  
Page 19 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Device ID  
Device ID is a 4-byte read only code identifying a type of product uniquely. This includes the product family code, configuration, and  
density of the product.  
Table 7. Device ID  
Device ID Description  
Device ID  
(4 bytes)  
31–21  
(11 bits)  
20–7  
(14 bits)  
6–3  
(4 bits)  
2–0  
(3 bits)  
Device  
Manufacturer ID  
00000110100  
00000110100  
00000110100  
Product ID  
Density ID  
0001  
Die Rev  
000  
000  
CY14C064PA  
CY14B064PA  
CY14E064PA  
0x0681C088  
0x0681C888  
0x0681D088  
00001110000001  
00001110010001  
00001110100001  
0001  
0001  
000  
The device ID is divided into four parts as shown in Table 9:  
1. Manufacturer ID (11 bits)  
4. Die Rev (3 bits)  
This is used to represent any major change in the design of the  
product. The initial setting of this is always 0x0.  
This is the JEDEC assigned manufacturer ID for Cypress.  
JEDEC assigns the manufacturer ID in different banks. The first  
three bits of the manufacturer ID represent the bank in which ID  
is assigned. The next eight bits represent the manufacturer ID.  
RDID (Device ID Read) Instruction  
This instruction is used to read the JEDEC assigned  
manufacturer ID and product ID of the device at SPI frequency  
upto 40 MHz. This instruction can be used to identify a device on  
the bus. RDID instruction can be issued by shifting the op-code  
for RDID in through the SI pin of nvSRAM after CS goes LOW.  
This is followed by nvSRAM shifting out the four bytes of device  
ID through the SO pin.  
Cypress’s manufacturer ID is 0x34 in bank 0. Therefore the  
manufacturer ID for all Cypress nvSRAM products is:  
Cypress ID - 000_0011_0100  
2. Product ID (14 bits)  
The product ID for device is shown in the Table 9.  
3. Density ID (4 bits)  
The 4 bit density ID is used as shown in Table 9 for indicating the  
64 Kb density of the product.  
Figure 27. RDID Instruction  
CS  
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15  
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31  
SCK  
SI  
Op-Code  
1
0
0
1
1
1
1
1
Byte - 4  
Byte - 3  
D7 D6 D5 D4 D3  
Byte - 2  
Byte - 1  
HI-Z  
D7 D6 D5 D4 D3  
D2  
D2  
D1  
D7 D6 D5 D4 D3  
MSB  
D1  
SO  
D2 D1  
D0  
D0 D7 D6 D5 D4 D3  
D0  
D2  
D1  
D0  
LSB  
4-Byte Device ID  
Document Number: 001-68249 Rev. *H  
Page 20 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
FAST_RDID (Fast Device ID Read) Instruction  
The FAST_RDID instruction allows you to read the JEDEC assigned manufacturer ID and product ID at SPI frequency above 40 MHz  
and up to 104 MHz (Max). FAST_RDID instruction can be issued by shifting the op-code for FAST_RDID in through the SI pin of  
nvSRAM followed by dummy byte after CS goes LOW. This is followed by nvSRAM shifting out the four bytes of device ID through  
the SO pin.  
Figure 28. FAST_RDID Instruction  
CS  
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15  
0
1
2
3
4
5
6
7
24 25 26 27 28 29 30 31  
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23  
8
SCK  
SI  
Dummy Byte  
Op-Code  
X
X
X
X
X
X
1
0
0
1
1
0
0
1
X
X
Byte - 4  
Byte - 3  
Byte - 2  
Byte - 1  
HI-Z  
D7 D6 D5 D4 D3  
D7 D6 D5 D4 D3  
D2  
D2  
D1  
D7 D6 D5 D4 D3  
MSB  
D1  
SO  
D2 D1  
D0  
D0 D7 D6 D5 D4 D3  
D2  
D0  
D1  
D0  
LSB  
4-Byte Device ID  
HOLD Pin Operation  
The HOLD pin is used to pause the serial communication. When  
the device is selected and a serial sequence is underway, HOLD  
is used to pause the serial communication with the master device  
without resetting the ongoing serial sequence. To pause, the  
HOLD pin must be brought LOW when the SCK pin is LOW. To  
resume serial communication, the HOLD pin must be brought  
HIGH when the SCK pin is LOW (SCK may toggle during HOLD).  
While the device serial communication is paused, inputs to the  
SI pin are ignored and the SO pin is in the high-impedance state.  
Figure 29. HOLD Operation  
CS  
SCK  
HOLD  
SO  
This pin can be used by the master with the CS pin to pause the  
serial communication by bringing the pin HOLD LOW and  
deselecting an SPI slave to establish communication with  
another slave device, without the serial communication being  
reset. The communication may be resumed at a later point by  
selecting the device and setting the HOLD pin HIGH.  
Document Number: 001-68249 Rev. *H  
Page 21 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
operation after tRTCp time while writing into the RTC registers for  
the modifications to be correctly recorded.  
Real Time Clock Operation  
nvTIME Operation  
Backup Power  
The CY14X064PA offers internal registers that contain clock,  
alarm, watchdog, interrupt, and control functions. The RTC  
registers occupy a separate address space from nvSRAM and  
are accessible through the Read RTC register and Write RTC  
register sequence on register addresses 0x00 to 0x0F. Internal  
double buffering of the time keeping registers prevents  
accessing transitional internal clock data during a read or write  
operation. Double buffering also circumvents disrupting normal  
timing counts or the clock accuracy of the internal clock when  
accessing clock data. Clock and alarm registers store data in  
BCD format.  
The RTC in the CY14X064PA is intended for permanently  
powered operation. The VRTCcap or VRTCbat pin is connected  
depending on whether a capacitor or battery is chosen for the  
application. When the primary power, VCC, fails and drops below  
VSWITCH the device switches to the backup power supply.  
The clock oscillator uses very little current, which maximizes the  
backup time available from the backup source. Regardless of the  
clock operation with the primary source removed, the data stored  
in the nvSRAM is secure, having been stored in the nonvolatile  
elements when power was lost.  
During backup operation, the CY14X064PA consumes a 0.45 µA  
(Typ) at room temperature. The user must choose capacitor or  
battery values according to the application.  
Clock Operations  
The clock registers maintain time up to 9,999 years in  
one-second increments. The time can be set to any calendar  
time and the clock automatically keeps track of days of the week  
and month, leap years, and century transitions. There are eight  
registers dedicated to the clock functions, which are used to set  
time with a write cycle and to read time with a read cycle. These  
registers contain the time of day in BCD format. Bits defined as  
‘0’ are currently not used and are reserved for future use by  
Cypress.  
Note: If a battery is applied to VRTCbat pin prior to VCC, the chip  
will draw high IBAK current. This occurs even if the oscillator is  
disabled. In order to maximize battery life, VCC must be applied  
before a battery is applied to VRTCbat pin.  
Backup time values based on maximum current specifications  
are shown in the following Table 8. Nominal backup times are  
approximately two times longer.  
Table 8. RTC Backup Time  
Reading the Clock  
Backup Time  
Capacitor Value  
The double buffered RTC register structure reduces the chance  
of reading incorrect data from the clock. Internal updates to the  
CY14X064PA time keeping registers are stopped when the read  
bit ‘R’ (in the flags register at 0x00) is set to ‘1’ before reading  
clock data to prevent reading of data in transition. Stopping the  
register updates does not affect clock accuracy.  
(CY14B064PA)  
0.1F  
0.47F  
1.0F  
60 hours  
12 days  
25 days  
Using a capacitor has the obvious advantage of recharging the  
backup source each time the system is powered up. If a battery  
is used, a 3-V lithium is recommended and the CY14X064PA  
sources current only from the battery when the primary power is  
removed. However, the battery is not recharged at any time by  
the CY14X064PA. The battery capacity must be chosen for total  
anticipated cumulative down time required over the life of the  
system.  
When a read sequence of RTC device is initiated, the update of  
the user timekeeping registers stops and does not restart until a  
‘0’ is written to the read bit ‘R’ (in the flags register at 0x00). After  
the end of read sequence, all the RTC registers are  
simultaneously updated within 20 ms.  
Setting the Clock  
A write access to the RTC device stops updates to the time  
keeping registers and enables the time to be set when the write  
bit ‘W’ (in the flags register at 0x00) is set to ‘1’. The correct day,  
date, and time is then written into the registers and must be in 24  
hour BCD format. The time written is referred to as the “Base  
Time”. This value is stored in nonvolatile registers and used in  
the calculation of the current time. When the write bit ‘W’ is  
cleared by writing ‘0’ to it, the values of timekeeping registers are  
transferred to the actual clock counters after which the clock  
resumes normal operation.  
Stopping and Starting the Oscillator  
The OSCEN bit in the calibration register at 0x08 controls the  
enable and disable of the oscillator. This bit is nonvolatile and is  
shipped to customers in the “enabled” (set to ‘0’) state. To  
preserve the battery life when the system is in storage, OSCEN  
must be set to ‘1’. This turns off the oscillator circuit, extending  
the battery life. If the OSCEN bit goes from disabled to enabled,  
it takes approximately one second (two seconds maximum) for  
the oscillator to start.  
If the time written to the timekeeping registers is not in the correct  
BCD format, each invalid nibble of the RTC registers continue  
counting to 0xF before rolling over to 0x0 after which RTC  
resumes normal operation.  
While system power is off, if the voltage on the backup supply  
(VRTCcap or VRTCbat) falls below their respective minimum level,  
the oscillator may fail.The CY14X064PA has the ability to detect  
oscillator failure when system power is restored. This is recorded  
in the Oscillator Fail Flag (OSCF) of the flags register at the  
address 0x00. When the device is powered on (VCC goes above  
Note After ‘W’ bit is set to ‘0’, values written into the timekeeping,  
alarm, calibration, and interrupt registers are transferred to the  
RTC time keeping counters in tRTCp time. These counter values  
must be saved to nonvolatile memory either by initiating a  
Software/Hardware STORE or AutoStore operation. While  
working in AutoStore disabled mode, perform a STORE  
V
SWITCH) the OSCEN bit is checked for the ‘enabled’ status. If  
the OSCEN bit is enabled and the oscillator is not active within  
the first 5 ms, the OSCF bit is set to ‘1’. The system must check  
for this condition and then write ‘0’ to clear the flag.  
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CY14C064PA  
CY14B064PA  
CY14E064PA  
Note that in addition to setting the OSCF flag bit, the time  
registers are reset to the ‘Base Time’, which is the value last  
written to the timekeeping registers. The control or calibration  
registers and the OSCEN bit are not affected by the ‘oscillator  
failed’ condition.  
Alarm  
The alarm function compares user programmed values of alarm  
time and date (stored in the registers 0x01–5) with the  
corresponding time of day and date values. When a match  
occurs, the alarm internal flag (AF) is set and an interrupt is  
generated on INT pin if Alarm Interrupt Enable (AIE) bit is set.  
The value of OSCF must be reset to ‘0’ when the time registers  
are written for the first time. This initializes the state of this bit  
which may have become set when the system was first powered  
on.  
There are four alarm match fields: date, hours, minutes, and  
seconds. Each of these fields has a match bit that is used to  
determine if the field is used in the alarm match logic. Setting the  
match bit to ‘0’ indicates that the corresponding field is used in  
the match process. Depending on the match bits, the alarm  
occurs as specifically as once a month or as frequently as once  
every minute. Selecting none of the match bits (all 1s) indicates  
that no match is required and therefore, alarm is disabled.  
Selecting all match bits (all 0s) causes an exact time and date  
match.  
To reset OSCF, set the write bit ‘W’ (in the flags register at 0x00)  
to a ‘1’ to enable writes to the flags register. Write a ‘0’ to the  
OSCF bit and then reset the write bit to ‘0’ to disable writes.  
Calibrating the Clock  
The RTC is driven by a quartz controlled crystal with a nominal  
frequency of 32.768 kHz. Clock accuracy depends on the quality  
of the crystal and calibration. The crystals available in market  
typically have an error of +20 ppm to +35 ppm. However,  
CY14X064PA employs a calibration circuit that improves the  
accuracy to +1/–2 ppm at 25 C. This implies an error of  
+2.5 seconds to -5 seconds per month.  
There are two ways to detect an alarm event: by reading the AF  
flag or monitoring the INT pin. The AF flag in the flags register at  
0x00 indicates that a date or time match has occurred. The AF  
bit is set to ‘1’ when a match occurs. Reading the flags register  
clears the alarm flag bit (and all others). A hardware interrupt pin  
may also be used to detect an alarm event.  
The calibration circuit adds or subtracts counts from the oscillator  
divider circuit to achieve this accuracy. The number of pulses that  
are suppressed (subtracted, negative calibration) or split (added,  
positive calibration) depends upon the value loaded into the five  
calibration bits found in calibration register at 0x08. The  
calibration bits occupy the five lower order bits in the calibration  
register. These bits are set to represent any value between ‘0’  
and 31 in binary form. Bit D5 is a sign bit, where a ‘1’ indicates  
positive calibration and a ‘0’ indicates negative calibration.  
Adding counts speeds the clock up and subtracting counts slows  
the clock down. If a binary ‘1’ is loaded into the register, it  
corresponds to an adjustment of 4.068 or –2.034 ppm offset in  
oscillator error, depending on the sign.  
To set, clear or enable an alarm, set the ‘W’ bit (in the flags  
register - 0x00) to ‘1’ to enable writes to alarm registers. After  
writing the alarm value, clear the ‘W’ bit back to ‘0’ for the  
changes to take effect.  
Note CY14X064PA requires the alarm match bit for seconds (bit  
‘D7’ in Alarm-Seconds register 0x02) to be set to ‘0’ for proper  
operation of Alarm Flag and Interrupt.  
Watchdog Timer  
The watchdog timer is a free running down counter that uses the  
32 Hz clock (31.25 ms) derived from the crystal oscillator. The  
oscillator must be running for the watchdog to function. It begins  
counting down from the value loaded in the watchdog timer  
register.  
Calibration occurs within a 64-minute cycle. The first 62 minutes  
in the cycle may, once per minute, have one second shortened  
by 128 or lengthened by 256 oscillator cycles. If a binary ‘1’ is  
loaded into the register, only the first two minutes of the  
64-minute cycle are modified. If a binary 6 is loaded, the first 12  
are affected, and so on. Therefore, each calibration step has the  
effect of adding 512 or subtracting 256 oscillator cycles for every  
125,829,120 actual oscillator cycles, that is, 4.068 or –2.034 ppm  
of adjustment per calibration step in the calibration register.  
The timer consists of a loadable register and a free running  
counter. On power-up, the watchdog time out value in register  
0x07 is loaded into the counter load register. Counting begins on  
power-up and restarts from the loadable value any time the  
Watchdog Strobe (WDS) bit is set to ‘1’. The counter is compared  
to the terminal value of ‘0’. If the counter reaches this value, it  
causes an internal flag and an optional interrupt output. You can  
prevent the time out interrupt by setting WDS bit to ‘1’ prior to the  
counter reaching ‘0’. This causes the counter to reload with the  
watchdog time out value and to be restarted. As long as the user  
sets the WDS bit prior to the counter reaching the terminal value,  
the interrupt and WDT flag never occur.  
To determine the required calibration, the CAL bit in the flags  
register (0x00) must be set to ‘1’. This causes the INT pin to  
toggle at a nominal frequency of 512 Hz. Any deviation  
measured from the 512 Hz indicates the degree and direction of  
the required correction. For example, a reading of 512.01024 Hz  
indicates a +20 ppm error. Hence, a decimal value of –10  
(001010b) must be loaded into the calibration register to offset  
this error.  
New time out values are written by setting the watchdog write bit  
to ‘0’. When the WDW is ‘0’, new writes to the watchdog time out  
value bits D5-D0 are enabled to modify the time out value. When  
WDW is ‘1’, writes to bits D5–D0 are ignored. The WDW function  
enables you to set the WDS bit without concern that the  
watchdog timer value is modified. A logical diagram of the  
watchdog timer is shown in Figure 30 on page 24. Note that  
setting the watchdog time out value to ‘0’ disables the watchdog  
function.  
Note Setting or changing the calibration register does not affect  
the test output frequency.  
To set or clear CAL, set the write bit ‘W’ (in the flags register at  
0x00) to ‘1’ to enable writes to the flags register. Write a value to  
CAL, and then reset the write bit to ‘0’ to disable writes.  
The output of the watchdog timer is the flag bit WDF that is set if  
the watchdog is allowed to time out. If the Watchdog Interrupt  
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CY14E064PA  
Enable (WIE) bit in the interrupt register is set, a hardware  
interrupt on INT pin is also generated on watchdog timeout. The  
flag and the hardware interrupt are both cleared when user reads  
the flag registers.  
Backup Power Monitor  
The CY14X064PA provides a backup power monitoring system  
which detects the backup power (either battery or capacitor  
backup) failure. The backup power fail flag (BPF) is issued on  
the next power-up in case of backup power failure. The BPF flag  
Figure 30. Watchdog Timer Block Diagram  
is set in the event of backup voltage falling lower than VBAKFAIL  
.
The backup power is monitored even while the RTC is running  
in backup mode. Low voltage detected during backup mode is  
flagged through the BPF flag. BPF can hold the data only until a  
defined low level of the back-up voltage (VDR).  
Clock  
Oscillator  
1 Hz  
Divider  
32.768 KHz  
32 Hz  
Zero  
Compare  
Interrupts  
WDF  
Counter  
The CY14X064PA has a flags register, interrupt register, and  
Interrupt logic that can signal interrupt to the microcontroller.  
There are three potential sources for interrupt: watchdog timer,  
power monitor, and alarm timer. Each of these can be individually  
enabled to drive the INT pin by appropriate setting in the interrupt  
register (0x06). In addition, each has an associated flag bit in the  
flags register (0x00) that the host processor uses to determine  
the cause of the interrupt. The INT pin driver has two bits that  
specify its behavior when an interrupt occurs.  
Load  
WDS  
Register  
Q
D
WDW  
Q
Watchdog  
Register  
write to  
Watchdog  
Register  
An Interrupt is raised only if both a flag is raised by one of the  
three sources and the respective interrupt enable bit in interrupts  
register is enabled (set to ‘1’). After an interrupt source is active,  
two programmable bits, H/L and P/L, determine the behavior of  
the output pin driver on INT pin. These two bits are located in the  
interrupt register and can be used to drive level or pulse mode  
output from the INT pin. In pulse mode, the pulse width is  
internally fixed at approximately 200 ms. This mode is intended  
to reset a host microcontroller. In the level mode, the pin goes to  
its active polarity until the flags register is read by the user. This  
mode is used as an interrupt to a host microcontroller. The  
control bits are summarized in the section Interrupt Register.  
Programmable Square Wave Generator  
The square wave generator block uses the crystal output to  
generate a desired frequency on the INT pin of the device. The  
output frequency can be programmed to be one of these:  
1. 1Hz  
2. 512 Hz  
3. 4096 Hz  
4. 32768 Hz  
Interrupts are only generated while working on normal power and  
are not triggered when system is running in backup power mode.  
The square wave output is not generated while the device is  
running on backup power.  
Note CY14X064PA generates valid interrupts only after the  
Power-Up RECALL sequence is completed. All events on INT  
pin must be ignored for tFA duration after powerup.  
Power Monitor  
The CY14X064PA provides a power management scheme with  
power fail interrupt capability. It also controls the internal switch  
to backup power for the clock and protects the memory from low  
Interrupt Register  
V
CC access. The power monitor is based on an internal band gap  
Watchdog Interrupt Enable (WIE): When set to ‘1’, the  
watchdog timer drives the INT pin and an internal flag when a  
watchdog time out occurs. When WIE is set to ‘0’, the watchdog  
timer only affects the WDF flag in flags register.  
reference circuit that compares the VCC voltage to VSWITCH  
threshold.  
As described in the section AutoStore Operation on page 4,  
when VSWITCH is reached as VCC decays from power loss, a data  
STORE operation is initiated from SRAM to the nonvolatile  
elements, securing the last SRAM data state. Power is also  
switched from VCC to the backup supply (battery or capacitor) to  
operate the RTC oscillator.  
Alarm Interrupt Enable (AIE): When set to ‘1’, the alarm match  
drives the INT pin and an internal flag. When AIE is set to ‘0’, the  
alarm match only affects the AF flag in flags register.  
Power Fail Interrupt Enable (PFE): When set to ‘1’, the power  
fail monitor drives the pin and an internal flag. When PFE is set  
to ‘0’, the power fail monitor only affects the PF flag in flags  
register.  
When operating from the backup source, read and write  
operations to nvSRAM are inhibited and the RTC functions are  
not available to the user. The RTC clock continues to operate in  
the background. The updated RTC time keeping registers are  
available to the user after VCC is restored to the device (see  
AutoStore or Power-Up RECALL on page 37).  
Square Wave Enable (SQWE): When set to ‘1’, a square wave  
of programmable frequency is generated on the INT pin. The  
frequency is decided by the SQ1 and SQ0 bits of the interrupts  
register. This bit is nonvolatile and survives power cycle. The  
SQWE bit over rides all other interrupts. However, CAL bit will  
take precedence over the square wave generator. This bit  
defaults to ‘0’ from factory.  
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CY14C064PA  
CY14B064PA  
CY14E064PA  
High/Low (H/L): When set to a ‘1’, the INT pin is active HIGH  
and the driver mode is push pull. The INT pin drives HIGH only  
when VCC is greater than VSWITCH. When set to a ‘0’, the INT pin  
is active LOW and the drive mode is open drain. The INT pin  
must be pulled up to Vcc by a 10 k resistor while using the  
interrupt in active LOW mode.  
the INT pin is programmed for Level mode, then the condition  
clears and the INT pin returns to its inactive state. If the pin is  
programmed for pulse mode, then reading the flag also clears  
the flag and the pin. The pulse does not complete its specified  
duration if the flags register is read. If the INT pin is used as a  
host reset, the flags register is not read during a reset.  
Pulse/Level (P/L): When set to a ‘1’ and an interrupt occurs, the  
INT pin is driven for approximately 200 ms. When P/L is set to a  
‘0’, the INT pin is driven HIGH or LOW (determined by H/L) until  
the flags register is read.  
This summary table shows the state of the INT pin.  
Table 10. State of the INT pin  
CAL  
SQWE  
WIE/AIE/PFE INT Pin Output  
SQ1 and SQ0. These bits are used together to fix the frequency  
of square wave on INT pin output when SQWE bit is set to ‘1’.  
These bits are nonvolatile and survive power cycle. The output  
frequency is decided as per the following table.  
1
0
X
1
X
X
512 Hz  
Square Wave  
Output  
0
0
0
0
1
0
Alarm  
HI-Z  
Table 9. SQW Output Selection  
SQ1  
SQ0  
Frequency  
1 Hz  
Comment  
1 Hz signal  
0
0
1
1
0
1
0
1
Flags Register  
512 Hz  
Useful for calibration  
4 kHz clock output  
The flags register has three flag bits: WDF, AF, and PF, which  
can be used to generate an interrupt. These flag are set by the  
watchdog timeout, alarm match, or power fail monitor  
respectively. The processor can either poll this register or enable  
interrupts to be informed when a flag is set. These flags are  
automatically reset after the register is read. The flags register is  
automatically loaded with the value 0x00 on power-up (except  
for the OSCF bit. See Stopping and Starting the Oscillator on  
page 22).  
4096 Hz  
32768 Hz  
Oscillator output  
frequency  
When an enabled interrupt source activates the INT pin, an  
external host reads the flag registers to determine the cause.  
Remember that all flag are cleared when the register is read. If  
Figure 31. Interrupt Block Diagram  
WIE  
Watchdog  
Timer  
WDF  
PFE  
VCC  
P/L  
Power  
Monitor  
WDF - Watchdog timer flag  
WIE - Watchdog interrupt  
enable  
PF  
512 Hz  
Clock  
Pin  
INT  
AIE  
Driver  
Mux  
Clock  
Alarm  
PF - Power fail flag  
PFE - Power fail enable  
Square  
Wave  
AF  
HI-Z  
Control  
H/L  
VSS  
AF - Alarm fag  
AIE - Alarm interrupt enable  
SEL Line  
P/L - Pulse level  
H/L - High/Low  
SQWE - Square wave enable  
SQWE  
CAL  
Priority  
Encoder  
WIE/PIE/  
AIE  
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Page 25 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
load capacitances C1 and C2 are inclusive of parasitic of the  
printed circuit board (PCB). The PCB parasitic includes the  
capacitance due to land pattern of crystal pads/pins, Xin/Xout  
pads and copper traces connecting crystal and device pins.  
RTC External Components  
The RTC requires connecting an external 32.768 kHz crystal and  
C1, C2 load capacitance as shown in the Figure 32. The figure  
shows the recommnded RTC external component values. The  
Figure 32. RTC Recommended Component Configuration [3]  
Recommended Values  
Y1 = 32.768 KHz (12.5 pF)  
C
C
= 12 pF  
= 69 pF  
1
2
X
C1  
out  
Y1  
Note: The recommended values for C1 and C2 includ  
X
C2  
in  
board trace capacitance.  
Note  
3. For nonvolatile static random access memory (nvSRAM) real time clock (RTC) design guidelines and best practices , refer application note AN61546.  
Document Number: 001-68249 Rev. *H  
Page 26 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Keep Xin and Xout trace width lesser than 8 mils. Wider trace  
width leads to larger trace capacitance. The larger these bond  
pads and traces are, the more likely it is that noise can couple  
from adjacent signals.  
PCB Design Considerations for RTC  
RTC crystal oscillator is a low current circuit with high impedance  
nodes on their crystal pins. Due to lower timekeeping current of  
RTC, the crystal connections are very sensitive to noise on the  
board. Hence it is necessary to isolate the RTC circuit from other  
signals on the board.  
Shield the Xin and Xout signals by providing a guard ring around  
the crystal circuitry. This guard ring prevents noise coupling  
from neighboring signals.  
It is also critical to minimize the stray capacitance on the PCB.  
Stray capacitances add to the overall crystal load capacitance  
and therefore cause oscillation frequency errors. Proper  
bypassing and careful layout are required to achieve the  
optimum RTC performance.  
Take care while routing any other high speed signal in the  
vicinity of RTC traces. The more the crystal is isolated from  
other signals on the board, the less likely it is that noise is  
coupled into the crystal. Maintain a minimum of 200 mil  
separation between the Xin, Xout traces and any other high  
speed signal on the board.  
Layout requirements  
The board layout must adhere to (but not limited to) the following  
guidelines during routing RTC circuitry. Following these guide-  
lines help you achieve optimum performance from the RTC  
design.  
No signals should run underneath crystal components on the  
same PCB layer.  
Create an isolated solid copper plane on adjacent PCB layer  
and underneath the crystal circuitry to prevent unwanted noise  
coupled from traces routed on the other signal layers of the  
PCB. The local plane should be separated by at least 40 mils  
from the neighboring plane on the same PCB layer. The solid  
plane should be in the vicinity of RTC components only and its  
perimeter should be kept equal to the guard ring perimeter.  
Figure 33 shows the recommended layout for RTC circuit.  
It is important to place the crystal as close as possible to the  
Xin and Xout pins. Keep the trace lengths between the crystal  
and RTC equal in length and as short as possible to reduce the  
probability of noise coupling by reducing the length of the  
antenna.  
Figure 33. Recommended Layout for RTC  
Top component layer: L1  
Ground plane layer: L2  
C1  
Isolated ground plane on  
layer 2 : L2  
Y1  
Guard ring - Top (Component)  
layer: L1  
C2  
System ground  
Via: Via connects to system ground  
plane on L2  
Via: Via connects to isolated  
ground plane on L2  
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CY14C064PA  
CY14B064PA  
CY14E064PA  
Table 11. RTC Register Map [4, 5]  
Register  
BCD Format Data  
Function/Range  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0x0F  
0x0E  
10s years  
Years  
Years: 00–99  
0
0
0
10s  
months  
Months  
Months: 01–12  
0x0D  
0x0C  
0x0B  
0x0A  
0x09  
0x08  
0
0
0
0
0
0
0
0
10s day of month  
Day of month  
Day of week  
Day of month: 01–31  
Day of week: 01–07  
Hours: 00–23  
0
0
0
10s hours  
Hours  
Minutes  
Seconds  
10s minutes  
10s seconds  
Minutes: 00–59  
Seconds: 00–59  
Calibration values [6]  
OSCEN  
(0)  
0
Cal sign  
(0)  
Calibration (00000)  
0x07  
0x06  
WDS (0) WDW (0)  
WDT (000000)  
Watchdog [6]  
Interrupts [6]  
WIE (0)  
AIE (0)  
PFE (0)  
SQWE  
(0)  
H/L (1)  
P/L (0)  
SQ1 (0) SQ0 (0)  
0x05  
0x04  
0x03  
0x02  
0x01  
0x00  
M (1)  
M (1)  
M (1)  
M (1)  
0
0
10s alarm date  
10s alarm hours  
Alarm day  
Alarm, day of month: 01–31  
Alarm, hours: 00–23  
Alarm, minutes: 00–59  
Alarm, seconds: 00–59  
Centuries: 00–99  
Alarm hours  
Alarm minutes  
Alarm seconds  
Centuries  
10s alarm minutes  
10s alarm seconds  
10s centuries  
WDF  
AF  
PF  
OSCF[7]  
BPF[7]  
CAL (0)  
W (0)  
R (0)  
Flags [6]  
Notes  
4. ( ) designates values shipped from the factory.  
5. The unused bits of RTC registers are reserved for future use and should be set to ‘0’.  
6. This is a binary value, not a BCD value.  
7. When user resets OSCF and BPF flag bits, the flags register will be updated after t  
time.  
RTCp  
Document Number: 001-68249 Rev. *H  
Page 28 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Table 12. Register Map Detail  
Register  
Description  
Time Keeping - Years  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0x0F  
10s years  
Years  
Contains the lower two BCD digits of the year. Lower nibble (four bits) contains the value for years; upper nibble (four  
bits) contains the value for 10s of years. Each nibble operates from 0 to 9. The range for the register is 0–99.  
Time Keeping - Months  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0x0E  
0x0D  
0
0
0
10s month  
Months  
Contains the BCD digits of the month. Lower nibble (four bits) contains the lower digit and operates from 0 to 9; upper  
nibble (one bit) contains the upper digit and operates from 0 to 1. The range for the register is 1–12.  
Time Keeping - Date  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0
0
10s day of month  
Day of month  
Contains the BCD digits for the date of the month. Lower nibble (four bits) contains the lower digit and operates from  
0 to 9; upper nibble (two bits) contains the 10s digit and operates from 0 to 3. The range for the register is 1–31. Leap  
years are automatically adjusted for.  
Time Keeping - Day  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0
0
0
0
0
Day of week  
0x0C  
Lower nibble (three bits) contains a value that correlates to day of the week. Day of the week is a ring counter that  
counts from 1 to 7 then returns to 1. The user must assign meaning to the day value, because the day is not integrated  
with the date.  
Time Keeping - Hours  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0x0B  
0x0A  
0
0
10s hours  
Hours  
Contains the BCD value of hours in 24 hour format. Lower nibble (four bits) contains the lower digit and operates from  
0 to 9; upper nibble (two bits) contains the upper digit and operates from 0 to 2. The range for the register is 0–23.  
Time Keeping - Minutes  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0
10s minutes  
Minutes  
Contains the BCD value of minutes. Lower nibble (four bits) contains the lower digit and operates from 0 to 9; upper  
nibble (three bits) contains the upper minutes digit and operates from 0 to 5. The range for the register is 0–59.  
Time Keeping - Seconds  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0x09  
0X08  
0
10s seconds  
Seconds  
Contains the BCD value of seconds. Lower nibble (four bits) contains the lower digit and operates from 0 to 9; upper  
nibble (three bits) contains the upper digit and operates from 0 to 5. The range for the register is 0–59.  
Calibration/Control  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
OSCEN  
0
Calibration  
sign  
Calibration  
OSCEN Oscillator Enable. When set to ‘1’, the oscillator is stopped. When set to ‘0’, the oscillator runs. Disabling the oscillator  
saves battery or capacitor power during storage.  
Calibration Determines if the calibration adjustment is applied as an addition (1) to or as a subtraction (0) from the time-base.  
Sign  
Document Number: 001-68249 Rev. *H  
Page 29 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Table 12. Register Map Detail (continued)  
Register  
Description  
Calibration These five bits control the calibration of the clock.  
Watchdog Timer  
0x07  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
WDS  
WDW  
WDT  
WDS  
Watchdog Strobe. Setting this bit to ‘1’ reloads and restarts the watchdog timer. Setting the bit to ‘0’ has no effect. The  
bit is cleared automatically after the watchdog timer is reset. The WDS bit is write only. Reading it always returns a ‘0’.  
WDW  
Watchdog Write Enable. Setting this bit to ‘1’ disables any WRITE to the watchdog timeout value (D5–D0). This enables  
the user to set the watchdog strobe bit without disturbing the timeout value. Setting this bit to ‘0’ allows bits D5–D0 to  
be written to the watchdog register when the next write cycle is complete. This function is explained in more detail in  
Watchdog Timer on page 23.  
WDT  
Watchdog Timeout Selection. The watchdog timer interval is selected by the 6-bit value in this register. It represents a  
multiplier of the 32 Hz count (31.25 ms). The range of timeout value is 31.25 ms (a setting of 1) to 2 seconds (setting  
of 3 Fh). Setting the watchdog timer register to 0 disables the timer. These bits can be written only if the WDW bit was  
set to ‘0’ on a previous cycle.  
Interrupt Status/Control  
0x06  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
WIE  
AIE  
PFE  
SQWE  
H/L  
P/L  
SQ1  
SQ0  
WIE  
AIE  
Watchdog Interrupt Enable. When set to ‘1’ and a watchdog timeout occurs, the watchdog timer drives the INT pin and  
the WDF flag. When set to ‘0’, the watchdog timeout affects only the WDF flag.  
Alarm Interrupt Enable. When set to ‘1’, the alarm match drives the INT pin and the AF flag. When set to ‘0’, the alarm  
match only affects the AF flag.  
PFE  
Power Fail Enable. When set to ‘1’, the alarm match drives the INT pin and the PF flag. When set to ‘0’, the power fail  
monitor affects only the PF flag.  
SQWE  
Square Wave Enable. When set to ‘1’, a square wave is driven on the INT pin with frequency programmed using SQ1  
and SQ0 bits. The square wave output takes precedence over interrupt logic. If the SQWE bit is set to ‘1’. when an  
enabled interrupt source becomes active, only the corresponding flag is raised and the INT pin continues to drive the  
square wave.  
H/L  
P/L  
High/Low. When set to ‘1’, the INT pin is driven active HIGH. When set to ‘0’, the INT pin is open drain, active LOW.  
Pulse/Level. When set to ‘1’, the INT pin is driven active (determined by H/L) by an interrupt source for approximately  
200 ms. When set to ‘0’, the INT pin is driven to an active level (as set by H/L) until the flags register is read.  
SQ1, SQ0 SQ1, SQ0. These bits are used to decide the frequency of the Square wave on the INT pin output when SQWE bit is  
set to ‘1’. The following is the frequency output for each combination of (SQ1, SQ0):  
(0, 0) - 1 Hz  
(0, 1) - 512 Hz  
(1, 0) - 4096 Hz  
(1, 1) - 32768 Hz  
Alarm - Day  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
Alarm date  
D0  
0x05  
M
0
10s alarm date  
Contains the alarm value for the date of the month and the mask bit to select or deselect the date value.  
M
Match. When this bit is set to ‘0’, the date value is used in the alarm match. Setting this bit to ‘1’ causes the match circuit  
to ignore the date value.  
Alarm - Hours  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
Alarm hours  
D0  
0x04  
M
0
10s alarm hours  
Contains the alarm value for the hours and the mask bit to select or deselect the hours value.  
M
Match. When this bit is set to ‘0’, the hours value is used in the alarm match. Setting this bit to ‘1’ causes the match  
circuit to ignore the hours value.  
Document Number: 001-68249 Rev. *H  
Page 30 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Table 12. Register Map Detail (continued)  
Register  
Description  
Alarm - Minutes  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0x03  
M
10s alarm minutes  
Alarm minutes  
Contains the alarm value for the minutes and the mask bit to select or deselect the minutes value.  
M
Match. When this bit is set to ‘0’, the minutes value is used in the alarm match. Setting this bit to ‘1’ causes the match  
circuit to ignore the minutes value.  
Alarm - Seconds  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0x02  
M
10s alarm seconds  
Alarm seconds  
Contains the alarm value for the seconds and the mask bit to select or deselect the seconds’ value.  
M
Match. When this bit is set to ‘0’, the seconds value is used in the alarm match. Setting this bit to ‘1’ causes the match  
circuit to ignore the seconds value.  
Time Keeping - Centuries  
0x01  
D7  
D6  
D5  
10s centuries  
D4  
D3  
D2  
D1  
Centuries  
D0  
Contains the BCD value of centuries. Lower nibble contains the lower digit and operates from 0 to 9; upper nibble  
contains the upper digit and operates from 0 to 9. The range for the register is 0-99 centuries.  
Flags  
0x00  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
WDF  
AF  
PF  
OSCF  
BPF  
CAL  
W
R
WDF  
AF  
Watchdog Timer Flag. This read only bit is set to ‘1’ when the watchdog timer is allowed to reach 0 without being reset  
by the user. It is cleared to ‘0’ when the flags register is read or on power-up  
Alarm Flag. This read only bit is set to ‘1’ when the time and date match the values stored in the alarm registers with  
the match bits = ‘0’. It is cleared when the flags register is read or on power-up.  
PF  
Power Fail Flag. This read only bit is set to ‘1’ when power falls below the power fail threshold VSWITCH. It is cleared  
when the flags register is read.  
OSCF  
Oscillator Fail Flag. Set to ‘1’ on power-up if the oscillator is enabled and not running in the first 5 ms of operation. This  
indicates that RTC backup power failed and clock value is no longer valid. This bit survives power cycle and is never  
cleared internally by the chip. The user must check for this condition and write '0' to clear this flag. When user resets  
OSCF flag bit, the bit will be updated after tRTCp time.  
BPF  
Backup Power Fail Flag. Set to ‘1’ on power-up if the backup power (battery or capacitor) failed. The backup power fail  
condition is determined by the voltage falling below their respective minimum specified voltage. BPF can hold the data  
only until a defined low level of the back-up voltage (VDR). User must reset this bit to clear this flag. When user resets  
BPF flag bit, the bit will be updated after tRTCp time.  
CAL  
W
Calibration Mode. When set to ‘1’, a 512 Hz square wave is output on the INT pin. When set to ‘0’, the INT pin resumes  
normal operation. This bit takes priority than SQ0/SQ1 and other functions. This bit defaults to ‘0’ (disabled) on power-up.  
Write Enable: Setting the ‘W’ bit to ‘1’ freezes updates of the RTC registers. The user can then write to RTC registers,  
alarm registers, calibration register, interrupt register and flags register. Setting the ‘W’ bit to ‘0’ causes the contents of  
the RTC registers to be transferred to the time keeping counters if the time has changed. This transfer process takes  
tRTCp time to complete. This bit defaults to 0 on power-up.  
R
Read Enable: Setting ‘R’ bit to ‘1’, stops clock updates to user RTC registers so that clock updates are not seen during  
the reading process. Set ‘R’ bit to ‘0’ to resume clock updates to the holding register. Setting this bit does not require  
‘W’ bit to be set to ‘1’. This bit defaults to ‘0’ on power-up.  
Document Number: 001-68249 Rev. *H  
Page 31 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Transient voltage (< 20 ns) on  
any pin to ground potential ................. –2.0 V to VCC + 2.0 V  
Maximum Ratings  
Exceeding maximum ratings may shorten the useful life of the  
device. These user guidelines are not tested.  
Package power dissipation  
capability (TA = 25 °C) ................................................. 1.0 W  
Storage temperature ................................ –65 C to +150 C  
Surface mount lead soldering  
temperature (3 seconds) ......................................... +260 C  
Maximum accumulated storage time  
At 150 C ambient temperature ...................... 1000 h  
At 85 C ambient temperature .................... 20 Years  
Maximum junction temperature ................................. 150 C  
DC output current (1 output at a time, 1s duration) .... 15 mA  
Static discharge voltage  
(per MIL-STD-883, Method 3015) ..........................> 2001 V  
Supply voltage on VCC relative to VSS  
Latch-up current ....................................................> 140 mA  
CY14C064PA: ...................................–0.5 V to +3.1 V  
CY14B064PA: ...................................–0.5 V to +4.1 V  
CY14E064PA: ...................................–0.5 V to +7.0 V  
DC voltage applied to outputs  
Operating Range  
Ambient  
Temperature  
Device  
Range  
VCC  
in High Z state ....................................0.5 V to VCC + 0.5 V  
CY14C064PA Industrial –40 C to +85 C 2.4 V to 2.6 V  
Input voltage .......................................0.5 V to VCC + 0.5 V  
CY14B064PA  
CY14E064PA  
2.7 V to 3.6 V  
4.5 V to 5.5 V  
DC Electrical Characteristics  
Over the Operating Range  
Parameter  
VCC  
Description  
Power supply  
Test Conditions  
CY14C064PA  
Min  
2.4  
2.7  
4.5  
Typ [8]  
2.5  
3.0  
5.0  
Max  
2.6  
3.6  
5.5  
3
Unit  
V
CY14B064PA  
CY14E064PA  
CY14C064PA  
CY14B064PA  
CY14E064PA  
V
V
ICC1  
Average VCC current  
fSCK = 40 MHz;  
Values obtained  
without output loads  
(IOUT = 0 mA)  
mA  
4
mA  
mA  
fSCK = 104 MHz;  
10  
Values obtained without output  
loads (IOUT = 0 mA)  
ICC2  
ICC3  
Average VCC current during  
STORE  
All inputs don’t care, VCC = max  
Average current for duration tSTORE  
3
1
mA  
mA  
Average VCC current  
All inputs cycling at CMOS levels.  
Values obtained without output  
loads (IOUT = 0 mA)  
f
SCK = 1 MHz;  
VCC = VCC(Typ), 25 °C  
ICC4  
ISB  
Average VCAP current during  
AutoStore cycle  
All inputs don't care. Average  
current for duration tSTORE  
3
mA  
VCC standby current  
Sleep mode current  
CS > (VCC – 0.2 V).  
250  
A  
V
IN < 0.2 V or > (VCC – 0.2 V).  
‘W’ bit set to ‘0’. Standby current  
level after nonvolatile cycle is  
complete. Inputs are static.  
f
SCK = 0 MHz.  
IZZ  
tSLEEP time after SLEEP instruction  
is registered. All inputs are static  
and configured at CMOS logic level.  
8
A  
A  
[9]  
IIX  
Input leakage current (except  
HSB)  
–1  
+1  
Input leakage current (for HSB)  
Off state output leakage current  
–100  
–1  
+1  
+1  
A  
A  
IOZ  
Notes  
8. Typical values are at 25 °C, V = V  
. Not 100% tested.  
CC(Typ)  
CC  
9. The HSB pin has I  
= -2 µA for V of 2.4 V when both active HIGH and LOW drivers are disabled. When they are enabled standard V and V are valid. This  
OUT  
O
H
O
H
O
L
parameter is characterized but not tested.  
Document Number: 001-68249 Rev. *H  
Page 32 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
DC Electrical Characteristics (continued)  
Over the Operating Range  
Parameter  
VIH  
Description  
Input HIGH voltage  
Test Conditions  
CY14C064PA  
Min  
1.7  
2.0  
Typ [8]  
Max  
Unit  
V
VCC + 0.5  
VCC + 0.5  
CY14B064PA  
CY14E064PA  
V
VIL  
Input LOW voltage  
Output HIGH voltage  
Output LOW voltage  
Storage capacitor  
CY14C064PA Vss – 0.5  
CY14B064PA Vss – 0.5  
CY14E064PA  
0.7  
0.8  
V
V
VOH  
VOL  
VCAP  
IOUT = –1 mA  
IOUT = –2 mA  
CY14C064PA  
CY14B064PA  
2.0  
2.4  
V
V
CY14E064PA VCC – 0.4  
IOUT = 2 mA  
CY14C064PA  
CY14B064PA  
CY14E064PA  
0.4  
0.4  
V
V
I
OUT = 4 mA  
[10]  
Between VCAP pin CY14C064PA  
170  
42  
220  
47  
270  
180  
F  
F  
and VSS  
CY14B064PA  
CY14E064PA  
[11, 12]  
VVCAP  
Maximum voltage driven on VCAP VCC = Max  
pin by the device  
CY14C064PA  
CY14B064PA  
CY14E064PA  
VCC  
V
V
VCC – 0.5  
Data Retention and Endurance  
Over the Operating Range  
Parameter  
Description  
Min  
20  
Unit  
Years  
K
DATAR  
NVC  
Data retention  
Nonvolatile STORE operations  
1,000  
Capacitance  
Parameter [12]  
Description  
Input capacitance  
Test Conditions  
Test Conditions  
Max  
7
Unit  
pF  
CIN  
TA = 25 C, f = 1 MHz,  
V
CC = VCC(Typ)  
COUT  
Output pin capacitance  
7
pF  
Thermal Resistance  
Parameter [12]  
Description  
16-pin SOIC Unit  
JA  
Thermal resistance  
(junction to ambient)  
Test conditions follow standard test methods and  
procedures for measuring thermal impedance, per  
EIA/JESD51.  
56.68  
C/W  
JC  
Thermal resistance  
(junction to case)  
32.11  
C/W  
Notes  
10. Min V  
value guarantees that there is a sufficient charge available to complete a successful AutoStore operation. Max V  
value guarantees that the capacitor on  
CAP  
CAP  
V
is charged to a minimum voltage during a Power-Up RECALL cycle so that an immediate power-down cycle can complete a successful AutoStore. Therefore it  
CAP  
is always recommended to use a capacitor within the specified min and max limits. Refer application note AN43593 for more details on V  
options.  
CAP  
11. Maximum voltage on V  
pin (V  
) is provided for guidance when choosing the V  
capacitor. The voltage rating of the V capacitor across the operating  
CAP  
VCAP  
CAP  
CAP  
temperature range should be higher than the V  
voltage.  
VCAP  
12. These parameters are guaranteed by design and are not tested.  
Document Number: 001-68249 Rev. *H  
Page 33 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
AC Test Loads and Waveforms  
Figure 34. AC Test Loads and Waveforms  
For 2.5 V (CY14C064PA):  
For Tri-state specs  
909  
909   
2.5 V  
2.5 V  
R1  
R1  
OUTPUT  
OUTPUT  
30 pF  
R2  
1290   
R2  
1290   
5 pF  
For 3 V (CY14B064PA):  
For Tri-state specs  
577   
577   
3.0 V  
3.0 V  
R1  
R1  
OUTPUT  
OUTPUT  
30 pF  
R2  
789   
R2  
789   
5 pF  
For 5 V (CY14E064PA):  
For Tri-state specs  
963   
R1  
963   
5.0 V  
5.0 V  
R1  
OUTPUT  
OUTPUT  
30 pF  
R2  
512   
R2  
512   
5 pF  
AC Test Conditions  
Description  
Input pulse levels  
CY14C064PA  
0 V to 2.5 V  
< 3 ns  
CY14B064PA  
0 V to 3 V  
< 3 ns  
CY14E064PA  
0 V to 3 V  
< 3 ns  
Input rise and fall times (10%–90%)  
Input and output timing reference levels  
1.25 V  
1.5 V  
1.5 V  
Document Number: 001-68249 Rev. *H  
Page 34 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
RTC Characteristics  
Over the Operating Range  
Parameter  
Description  
Min  
1.8  
Typ[13]  
Max  
3.6  
0.45  
Units  
V
VRTCbat  
RTC battery pin voltage  
RTC backup current  
3.0  
[14]  
IBAK  
TA (Min)  
25 °C  
µA  
µA  
µA  
V
(Refer Figure 32 for the recommended external componets  
for RTC)  
0.45  
TA (Max)  
TA (Min)  
25 °C  
0.60  
3.6  
3.6  
3.6  
2
[15]  
VRTCcap  
RTC capacitor pin voltage  
1.6  
1.5  
1.4  
3.0  
V
TA (Max)  
V
tOCS  
VBAKFAIL  
VDR  
RTC oscillator time to start  
1
sec  
V
Backup failure threshold  
1.8  
1.6  
2.2  
BPF flag retention voltage  
V
tRTCp  
RTC processing time from end of ‘W’ bit set to ‘0’  
RTC backup capacitor charge current limiting resistor  
1
ms  
RBKCHG  
350  
850  
AC Switching Characteristics  
Over the Operating Range  
Parameter [16]  
Description  
25 MHz (RDRTC Instruction) [17]  
40 MHz  
104 MHz  
Min Max  
Unit  
Cypress  
Alt.  
Min  
Max  
Min  
Max  
Parameter Parameter  
fSCK  
fSCK  
tWL  
tWH  
tCE  
tCES  
tCEH  
tSU  
tH  
Clock frequency, SCK  
Clock pulse width LOW  
Clock pulse width HIGH  
CS HIGH time  
18  
18  
20  
10  
10  
5
25  
11  
11  
20  
10  
10  
5
40  
4.5  
4.5  
20  
5
104  
MHz  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
[18]  
tCL  
tCH  
tCS  
[18]  
tCSS  
tCSH  
tSD  
CS setup time  
CS hold time  
5
Data in setup time  
Data in hold time  
HOLD hold time  
4
tHD  
5
5
3
tHH  
tHD  
tCD  
tV  
5
5
3
tSH  
HOLD setup time  
Output valid  
5
5
3
tCO  
15  
15  
15  
9
8
[18]  
tHHZ  
tHZ  
tLZ  
tHO  
tDIS  
HOLD to output high Z  
HOLD to output low Z  
Output hold time  
Output disable time  
15  
15  
8
[18]  
tHLZ  
tOH  
8
0
0
0
[18]  
tHZCS  
25  
20  
8
Notes  
13. Typical values are at 25 °C, V = V  
. Not 100% tested.  
CC(Typ)  
CC  
14. Current drawn from either V  
or V  
when V < V  
RTCcap  
RTCbat CC SWITCH.  
15. If V  
> 0.5 V or if no capacitor is connected to V  
pin, the oscillator will start in tOCS time. If a backup capacitor is connected and V  
< 0.5 V, the  
RTCcap  
RTCcap  
RTCcap  
capacitor must be allowed to charge to 0.5 V for oscillator to start.  
16. Test conditions assume signal transition time of 3 ns or less, timing reference levels of V /2, input pulse levels of 0 to V  
, and output loading of the specified  
CC(typ)  
CC  
I
/I and load capacitance shown in Figure 34.  
OL OH  
17. Applicable for RTC opcode cycles, address cycles and data out cycles.  
18. These parameters are guaranteed by design and are not tested.  
Document Number: 001-68249 Rev. *H  
Page 35 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Switching Waveforms  
Figure 35. Synchronous Data Timing (Mode 0)  
t
CS  
CS  
t
t
t
CSS  
CH  
CL  
t
CSH  
SCK  
t
t
SD  
HD  
SI  
VALID IN  
VALID IN  
VALID IN  
t
t
t
OH  
HZCS  
CO  
HI-Z  
HI-Z  
SO  
Figure 36. HOLD Timing  
CS  
SCK  
t
t
HH  
HH  
t
t
SH  
SH  
HOLD  
SO  
t
t
HLZ  
HHZ  
Document Number: 001-68249 Rev. *H  
Page 36 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
AutoStore or Power-Up RECALL  
Over the Operating Range  
CY14X064PA  
Parameter  
Description  
Unit  
Min  
Max  
40  
[19]  
Power-Up RECALL duration  
STORE cycle duration  
CY14C064PA  
CY14B064PA  
CY14E064PA  
ms  
ms  
ms  
ms  
ns  
V
tFA  
20  
20  
[20]  
[21]  
8
tSTORE  
tDELAY  
Time allowed to complete SRAM write cycle  
Low voltage trigger level  
25  
VSWITCH  
CY14C064PA  
CY14B064PA  
CY14E064PA  
2.35  
2.65  
4.40  
V
V
[22]  
VCC rise time  
150  
µs  
V
tVCCRISE  
[22]  
[22]  
HSB output disable voltage  
HSB high to nvSRAM active time  
HSB HIGH active time  
1.9  
5
VHDIS  
µs  
ns  
ms  
ms  
ms  
ms  
µs  
tLZHSB  
[22]  
500  
40  
tHHHD  
tWAKE  
Time for nvSRAM to wake up from SLEEP mode  
CY14C064PA  
CY14B064PA  
CY14E064PA  
20  
20  
tSLEEP  
Time to enter into SLEEP mode after Issuing SLEEP instruction  
Time to enter into standby mode after CS going HIGH  
8
[22]  
100  
tSB  
Switching Waveforms  
Figure 37. AutoStore or Power-Up RECALL[23]  
VCC  
VSWITCH  
VHDIS  
20  
20  
Note  
tVCCRISE  
tSTORE  
tSTORE  
Note  
tHHHD  
tHHHD  
23  
23  
Note  
Note  
HSB OUT  
AutoStore  
tDELAY  
tLZHSB  
tLZHSB  
tDELAY  
POWER-  
UP  
RECALL  
tFA  
tFA  
Read & Write  
Inhibited  
(RWI)  
Read & Write  
Read & Write  
POWER-UP  
RECALL  
BROWN  
OUT  
AutoStore  
POWER  
DOWN  
AutoStore  
POWER-UP  
RECALL  
Notes  
19. t starts from the time V rises above V  
SWITCH.  
FA  
CC  
20. If an SRAM write has not taken place since the last nonvolatile cycle, no AutoStore or Hardware STORE takes place.  
21. On a Hardware STORE and AutoStore initiation, SRAM write operation continues to be enabled for time t  
22. These parameters are guaranteed by design and are not tested.  
.
DELAY  
23. Read and Write cycles are ignored during STORE, RECALL, and while V is below V  
CC  
SWITCH.  
24. During power-up and power-down, HSB glitches when HSB pin is pulled up through an external resistor.  
Document Number: 001-68249 Rev. *H  
Page 37 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Software Controlled STORE/RECALL Cycles  
Over the Operating Range  
CY14X064PA  
Parameter  
tRECALL  
Description  
Unit  
Min  
Max  
600  
500  
RECALL duration  
µs  
µs  
[25, 26]  
tSS  
Soft sequence processing time  
Switching Waveforms  
Figure 38. Software STORE Cycle  
Figure 39. Software RECALL Cycle  
CS  
CS  
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
SCK  
SI  
SCK  
SI  
0
0
1
1
1
1
0
0
0
1
1
0
0
0
0
0
t
t
RECALL  
STORE  
HI-Z  
HI-Z  
RWI  
RDY  
RWI  
RDY  
Figure 40. AutoStore Enable Cycle  
Figure 41. AutoStore Disable Cycle  
CS  
CS  
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
SCK  
SI  
SCK  
SI  
0
0
0
1
1
0
0
1
0
1
0
1
1
0
0
1
t
SS  
t
SS  
HI-Z  
HI-Z  
RWI  
RDY  
RWI  
RDY  
Notes  
25. This is the amount of time it takes to take action on a soft sequence command. Vcc power must remain HIGH to effectively register command.  
26. Commands such as STORE and RECALL lock out I/O until operation is complete which further increases this time. See the specific command.  
Document Number: 001-68249 Rev. *H  
Page 38 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Hardware STORE Cycle  
Over the Operating Range  
CY14X064PA  
Parameter  
Description  
Unit  
Min  
Max  
tPHSB  
Hardware STORE pulse width  
15  
ns  
Switching Waveforms  
Figure 42. Hardware STORE Cycle [27]  
Write Latch set  
t
PHSB  
HSB (IN)  
t
STORE  
t
t
HHHD  
DELAY  
HSB (OUT)  
RWI  
t
LZHSB  
Write Latch not set  
t
PHSB  
HSB (IN)  
HSB pin is driven HIGH to V  
only by Internal  
CC  
100 K: resistor, HSB driver is disabled  
SRAM is disabled as long as HSB (IN) is driven LOW.  
HSB (OUT)  
RWI  
t
DELAY  
Note  
27. If an SRAM write has not taken place since the last nonvolatile cycle, no AutoStore or Hardware STORE takes place.  
Document Number: 001-68249 Rev. *H  
Page 39 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Ordering Information  
Ordering Code  
Package Diagram  
Package Type  
16-pin SOIC, 40 MHz  
Operating Range  
CY14B064PA-SFXIT  
51-85022  
Industrial  
CY14B064PA-SFXI  
All the above parts are Pb-free.  
Ordering Code Definitions  
CY 14 B 064 P A - 104 SF X I T  
Option:  
T - Tape and Reel  
Blank - Std.  
Temperature:  
I - Industrial (-40 to 85 °C)  
Pb-free  
Package:  
SF - 16-pin SOIC  
Frequency:  
Blank - 40 MHz  
104 - 104 MHz  
Die revision:  
Blank - No Rev  
A - 1st Rev  
P - Serial (SPI) nvSRAM with RTC  
Density:  
Voltage:  
C - 2.5 V  
B - 3.0 V  
E - 5.0 V  
064 - 64 Kb  
14 - nvSRAM  
Cypress  
Document Number: 001-68249 Rev. *H  
Page 40 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Package Diagram  
Figure 43. 16-pin SOIC (0.413 × 0.299 × 0.0932 Inches) Package Outline, 51-85022  
51-85022 *E  
Document Number: 001-68249 Rev. *H  
Page 41 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Acronyms  
Document Conventions  
Units of Measure  
Acronym  
Description  
Binary Coded Decimal  
BCD  
Symbol  
°C  
Unit of Measure  
CPHA  
CPOL  
CMOS  
CRC  
Clock Phase  
Clock Polarity  
degree Celsius  
farad  
F
Complementary Metal Oxide Semiconductor  
Cyclic Redundancy Check  
Hz  
kHz  
k  
MHz  
A  
mA  
F  
s  
hertz  
kilohertz  
kilohm  
EEPROM Electrically Erasable Programmable Read-Only  
Memory  
megahertz  
microampere  
milliampere  
microfarad  
microsecond  
millisecond  
nanosecond  
ohm  
EIA  
Electronic Industries Alliance  
Input/Output  
I/O  
JEDEC  
LSB  
Joint Electron Devices Engineering Council  
Least Significant Bit  
MSB  
Most Significant Bit  
ms  
ns  
nvSRAM  
OSCF  
OSCF  
RWI  
Non-volatile Static Random Access Memory  
Oscillator Fail Flag  
Oscillator Fail Flag  
%
percent  
Read and Write Inhibit  
pF  
ppm  
sec  
V
picofarad  
parts per million  
second  
RTC  
Real Time Clock  
RoHS  
SNL  
Restriction of Hazardous Substances  
Serial Number Lock  
volt  
SPI  
Serial Peripheral Interface  
Silicon-Oxide-Nitride-Oxide Semiconductor  
Small Outline Integrated Circuit  
Static Random Access Memory  
W
watt  
SONOS  
SOIC  
SRAM  
Document Number: 001-68249 Rev. *H  
Page 42 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Document History Page  
Document Title: CY14C064PA, CY14B064PA, CY14E064PA, 64-Kbit (8 K × 8) SPI nvSRAM with Real Time Clock  
Document Number: 001-68249  
Orig. of  
Change  
Submission  
Date  
Rev.  
ECN  
Description of Change  
**  
3202424  
3248510  
3386955  
GVCH  
GVCH  
GVCH  
03/22/2011 New data sheet.  
*A  
*B  
05/04/2011 Changed status from Preliminary to Final.  
09/28/2011 Updated Pin Definitions (Added Note 2 and referred the same note in VRTCcap  
VRTCbat, Xout, Xin and INT/SQW parameters).  
,
Updated SPI Operating Features (Updated Power-Up (description)).  
Updated Special Instructions (Updated SLEEP Instruction (description),  
updated Figure 23).  
Updated Device ID (Updated Table 7 (Added Device ID (4 bytes) column)).  
Updated Real Time Clock Operation (Added Note 3 and referred the same note  
in Figure ).  
Updated DC Electrical Characteristics (Changed maximum value of ICC2  
parameter from 2 mA to 3 mA, added Note 10 and referred the same note in  
VCAP parameter).  
Updated RTC Characteristics.  
Updated AC Switching Characteristics (Added Note 16 and referred the same  
note in Parameters column).  
Updated Package Diagram.  
*C  
3683851  
GVCH  
07/24/2012 Updated DC Electrical Characteristics (Added VVCAP parameter and its details,  
added Note 11 and referred the same note in VVCAP parameter, also referred  
Note 12 in VVCAP parameter).  
*D  
*E  
3762423  
3985113  
GVCH  
GVCH  
10/01/2012 Updated Maximum Ratings (Removed “Ambient temperature with power  
applied” and included “Maximum junction temperature”).  
04/29/2013 Updated RTC Characteristics:  
Changed maximum value of VBAKFAIL parameter from 2 V to 2.2 V.  
Updated Package Diagram:  
spec 51-85022 – Changed revision from *D to *E.  
*F  
4042118  
GVCH  
06/27/2013 Updated Real Time Clock Operation:  
Updated Backup Power (Added Note).  
Added RTC External Components.  
Moved Figure 32 from Flags Register section to RTC External Components  
section.  
Added PCB Design Considerations for RTC.  
*G  
*H  
4567905  
6033841  
GVCH  
GVCH  
11/12/2014 Added related documentation hyperlink in page 1.  
01/16/2018 Updated to the new template.  
Completing the Sunset review.  
Document Number: 001-68249 Rev. *H  
Page 43 of 44  
CY14C064PA  
CY14B064PA  
CY14E064PA  
Sales, Solutions, and Legal Information  
Worldwide Sales and Design Support  
Cypress maintains a worldwide network of offices, solution centers, manufacturer’s representatives, and distributors. To find the office  
closest to you, visit us at Cypress Locations.  
®
Products  
PSoC Solutions  
Arm® Cortex® Microcontrollers  
cypress.com/arm  
cypress.com/automotive  
cypress.com/clocks  
cypress.com/interface  
cypress.com/iot  
PSoC 1 | PSoC 3 | PSoC 4 | PSoC 5LP | PSoC 6 MCU  
Automotive  
Cypress Developer Community  
Clocks & Buffers  
Interface  
Community | Projects | Video | Blogs | Training | Components  
Technical Support  
Internet of Things  
Memory  
cypress.com/support  
cypress.com/memory  
cypress.com/mcu  
Microcontrollers  
PSoC  
cypress.com/psoc  
Power Management ICs  
Touch Sensing  
USB Controllers  
Wireless Connectivity  
cypress.com/pmic  
cypress.com/touch  
cypress.com/usb  
cypress.com/wireless  
© Cypress Semiconductor Corporation, 2011-2018. This document is the property of Cypress Semiconductor Corporation and its subsidiaries, including Spansion LLC (“Cypress”). This document,  
including any software or firmware included or referenced in this document (“Software”), is owned by Cypress under the intellectual property laws and treaties of the United States and other countries  
worldwide. Cypress reserves all rights under such laws and treaties and does not, except as specifically stated in this paragraph, grant any license under its patents, copyrights, trademarks, or other  
intellectual property rights. If the Software is not accompanied by a license agreement and you do not otherwise have a written agreement with Cypress governing the use of the Software, then Cypress  
hereby grants you a personal, non-exclusive, nontransferable license (without the right to sublicense) (1) under its copyright rights in the Software (a) for Software provided in source code form, to  
modify and reproduce the Software solely for use with Cypress hardware products, only internally within your organization, and (b) to distribute the Software in binary code form externally to end users  
(either directly or indirectly through resellers and distributors), solely for use on Cypress hardware product units, and (2) under those claims of Cypress's patents that are infringed by the Software (as  
provided by Cypress, unmodified) to make, use, distribute, and import the Software solely for use with Cypress hardware products. Any other use, reproduction, modification, translation, or compilation  
of the Software is prohibited.  
TO THE EXTENT PERMITTED BY APPLICABLE LAW, CYPRESS MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS DOCUMENT OR ANY SOFTWARE  
OR ACCOMPANYING HARDWARE, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. No computing  
device can be absolutely secure. Therefore, despite security measures implemented in Cypress hardware or software products, Cypress does not assume any liability arising out of any security breach,  
such as unauthorized access to or use of a Cypress product. In addition, the products described in these materials may contain design defects or errors known as errata which may cause the product  
to deviate from published specifications. To the extent permitted by applicable law, Cypress reserves the right to make changes to this document without further notice. Cypress does not assume any  
liability arising out of the application or use of any product or circuit described in this document. Any information provided in this document, including any sample design information or programming  
code, is provided only for reference purposes. It is the responsibility of the user of this document to properly design, program, and test the functionality and safety of any application made of this  
information and any resulting product. Cypress products are not designed, intended, or authorized for use as critical components in systems designed or intended for the operation of weapons, weapons  
systems, nuclear installations, life-support devices or systems, other medical devices or systems (including resuscitation equipment and surgical implants), pollution control or hazardous substances  
management, or other uses where the failure of the device or system could cause personal injury, death, or property damage (“Unintended Uses”). A critical component is any component of a device  
or system whose failure to perform can be reasonably expected to cause the failure of the device or system, or to affect its safety or effectiveness. Cypress is not liable, in whole or in part, and you  
shall and hereby do release Cypress from any claim, damage, or other liability arising from or related to all Unintended Uses of Cypress products. You shall indemnify and hold Cypress harmless from  
and against all claims, costs, damages, and other liabilities, including claims for personal injury or death, arising from or related to any Unintended Uses of Cypress products.  
Cypress, the Cypress logo, Spansion, the Spansion logo, and combinations thereof, WICED, PSoC, CapSense, EZ-USB, F-RAM, and Traveo are trademarks or registered trademarks of Cypress in  
the United States and other countries. For a more complete list of Cypress trademarks, visit cypress.com. Other names and brands may be claimed as property of their respective owners.  
Document Number: 001-68249 Rev. *H  
Revised January 16, 2018  
Page 44 of 44  

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