AT25PE20-SHN-B [DIALOG]
2-Mbit DataFlash-L Page Erase Serial Flash Memory;型号: | AT25PE20-SHN-B |
厂家: | Dialog Semiconductor |
描述: | 2-Mbit DataFlash-L Page Erase Serial Flash Memory |
文件: | 总64页 (文件大小:1119K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
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AT25PE20
2-Mbit DataFlash-L
Page Erase Serial Flash Memory
DATASHEET
Features
ò
ò
Single 1.65V - 3.6V supply
Serial Peripheral Interface (SPI) compatible
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Supports SPI modes 0 and 3
Supports RapidS™ operation
ò
ò
ò
Continuous read capability through entire array
ò
ò
ò
Up to 85MHz
Low-power read option up to 15MHz
Clock-to-output time (tV) of 6ns maximum
User configurable page size
ò
256 bytes per page (default)
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264 bytes per page (customer selectable option)
ò
ò
One SRAM data buffer (256/264 bytes)
Flexible programming options
ò
ò
ò
ò
Byte/Page Program (1 to 256/264 bytes) directly into main memory
Buffer Write
Buffer to Main Memory Page Program
Single Command Page Read-Modify-Write Option
ò
ò
Flexible erase options
ò
ò
ò
ò
Page Erase (256/264 bytes)
Block Erase (2KB)
Sector Erase (32KB)
Chip Erase (2-Mbits)
128-byte Security Register
128 bytes factory programmed with a unique identifier
ò
ò
ò
ò
Hardware and software controlled reset options
JEDEC Standard Manufacturer and Device ID Read
Low-power dissipation
ò
ò
ò
ò
300nA Ultra-Deep Power-Down current (typical)
5µA Deep Power-Down current (typical)
25µA Standby current (typical)
7mA Active Read current (typical)
ò
ò
ò
ò
Endurance: 100,000 program/erase cycles per page minimum
Data retention: 20 years
Complies with full industrial temperature range
Green (Pb/Halide-free/RoHS compliant) packaging options
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8-lead SOIC (0.150ʺ wide and 0.208" wide)
8-pad Ultra-thin DFN (5 x 6 x 0.6mm)
ò
DS-25PE20–139C–8/2018
Description
The Adesto® AT25PE20 is a 1.65V minimum, serial-interface sequential access Flash memory is ideally suited for a wide
variety of digital voice, image, program code, and data storage applications. The AT25PE20 also supports the RapidS
serial interface for applications requiring very high speed operation. Its 2,162,688 bits of memory are organized as 1,024
pages of 256 bytes (default) or 264 bytes (customer option) each. In addition to the main memory, AT25PE20 also
contains one SRAM buffer of 256/264 bytes. The Buffer can be used as additional system scratch memory, and E2PROM
emulation
(bit or byte alterability) can be easily handled with a self-contained three step read-modify-write operation.
Unlike conventional Flash memories that are accessed randomly with multiple address lines and a parallel interface, the
Adesto DataFlash-L® uses a serial interface to sequentially access its data. The simple sequential access dramatically
reduces active pin count, facilitates simplified hardware layout, increases system reliability, minimizes switching noise,
and reduces package size. The device is optimized for use in many commercial and industrial applications where
high-density, low-pin count, low-voltage, and low-power are essential.
To allow for simple in-system re-programmability, AT25PE20 does not require high input voltages for programming. The
device operates from a single 1.65V to 3.6V power supply for the erase and program and read operations. The
AT25PE20 is enabled through the Chip Select pin (CS) and accessed via a 3-wire interface consisting of the Serial Input
(SI), Serial Output (SO), and the Serial Clock (SCK).
All programming and erase cycles are self-timed.
1.
Pin Configurations and Pinouts
Figure 1-1. Pinouts
8-lead SOIC
Top View
8-pad UDFN
Top View
(through package)
CS
SO
1
2
3
4
8
7
6
5
Vcc
CS
SO
1
2
3
4
8
7
6
5
Vcc
RESET
SCK
SI
RESET
SCK
SI
WP
WP
GND
GND
Note: 1. The metal pad on the bottom of the UDFN package is not internally connected to a voltage potential.
This pad can be a “no connect” or connected to GND.
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Table 1-1. Pin Configurations
Asserted
State
Symbol
Name and Function
Type
Chip Select: Asserting the CS pin selects the device. When the CS pin is deasserted, the
device will be deselected and normally be placed in the standby mode (not Deep Power-Down
mode) and the output pin (SO) will be in a high-impedance state. When the device is
deselected, data will not be accepted on the input pin (SI).
CS
Low
Input
A high-to-low transition on the CS pin is required to start an operation and a low-to-high
transition is required to end an operation. When ending an internally self-timed operation such
as a program or erase cycle, the device will not enter the standby mode until the completion of
the operation.
Serial Clock: This pin is used to provide a clock to the device and is used to control the flow of
data to and from the device. Command, address, and input data present on the SI pin is
always latched on the rising edge of SCK, while output data on the SO pin is always clocked
out on the falling edge of SCK.
SCK
—
Input
Serial Input: The SI pin is used to shift data into the device. The SI pin is used for all data input
including command and address sequences. Data on the SI pin is always latched on the rising
edge of SCK. Data present on the SI pin will be ignored whenever the device is deselected (CS
is deasserted).
SI
—
—
Input
Serial Output: The SO pin is used to shift data out from the device. Data on the SO pin is
always clocked out on the falling edge of SCK. The SO pin will be in a high-impedance state
whenever the device is deselected (CS is deasserted).
SO
Output
Write Protect: When the WP pin is asserted, all sectors specified for protection by the Sector
Protection Register will be protected against program and erase operations regardless of
whether the Enable Sector Protection command has been issued or not. The WP pin functions
independently of the software controlled protection method. After the WP pin goes low, the
contents of the Sector Protection Register cannot be modified.
WP
If a program or erase command is issued to the device while the WP pin is asserted, the device
will simply ignore the command and perform no operation. The device will return to the idle
state once the CS pin has been deasserted.
Low
Input
The WP pin is internally pulled-high and may be left floating if hardware controlled protection
will not be used. However, it is recommended that the WP pin also be externally connected to
VCC whenever possible.
Reset: A low state on the reset pin (RESET) will terminate the operation in progress and reset
the internal state machine to an idle state. The device will remain in the reset condition as long
as a low level is present on the RESET pin. Normal operation can resume once the RESET pin
is brought back to a high level.
RESET
Low
Input
The device incorporates an internal power-on reset circuit, so there are no restrictions on the
RESET pin during power-on sequences. If this pin and feature is not utilized, then it is
recommended that the RESET pin be driven high externally.
Device Power Supply: The VCC pin is used to supply the source voltage to the device.
Operations at invalid VCC voltages may produce spurious results and should not be attempted.
VCC
—
—
Power
Ground: The ground reference for the power supply. GND should be connected to the system
ground.
GND
Ground
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2.
Block Diagram
Figure 2-1. Block Diagram
WP
Flash Memory Array
Page (256/264 bytes)
Buffer 1 (256/264 bytes)
SCK
CS
I/O Interface
RESET
V
CC
GND
SI
SO
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3.
Memory Array
To provide optimal flexibility, the AT25PE20 memory array is divided into three levels of granularity comprising of sectors,
blocks, and pages. Figure 3-1, Memory Architecture Diagram illustrates the breakdown of each level and details the
number of pages per sector and block. Program operations to the DataFlash-L can be done at the full page level or at the
byte level (a variable number of bytes). The erase operations can be performed at the chip, sector, block, or page level.
Figure 3-1. Memory Architecture Diagram
Sector Architecture
Block Architecture
Page Architecture
Block 0
Block 1
Block 2
8 Pages
Page 0
Page 1
Sector 0a
Sector 0a = 8 pages
2,048/2,112 bytes
Sector 0b = 120 pages
30,720/31,680 bytes
Page 6
Page 7
Page 8
Page 9
Block 14
Block 15
Block 16
Block 17
Sector 1 = 128 pages
32,768/33,792 bytes
Page 14
Page 15
Page 16
Page 17
Page 18
Block 30
Block 31
Block 112
Block 113
Sector 6 = 128 pages
32,768/33,792 bytes
Sector 7 = 128 pages
32,768/33,792 bytes
Block 126
Block 127
Page 1,022
Page 1,023
Block = 2,048/2,112 bytes
Page = 256/264 bytes
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4.
Device Operation
The device operation is controlled by instructions from the host processor. The list of instructions and their associated
opcodes are contained in Table 15-1 on page 35 through Table 15-4 on page 36. A valid instruction starts with the falling
edge of CS followed by the appropriate 8-bit opcode and the Buffer or main memory address location. While the CS pin
is low, toggling the SCK pin controls the loading of the opcode and the Buffer or main memory address location through
the SI (Serial Input) pin. All instructions, addresses, and data are transferred with the Most Significant Bit (MSB) first.
Three address bytes are used to address memory locations in either the main memory array or in the Buffer. The three
address bytes will be comprised of a number of dummy bits and a number of actual device address bits, with the number
of dummy bits varying depending on the operation being performed and the selected device page size. Buffer addressing
for the optional DataFlash-L page size (264 bytes) is referenced in the datasheet using the terminology BFA8 - BFA0 to
denote the nine address bits required to designate a byte address within the Buffer. The main memory addressing is
referenced using the terminology PA9 - PA0 and BA8 - BA0, where PA9 - PA0 denotes the 10 address bits required to
designate a page address, and BA8 - BA0 denotes the nine address bits required to designate a byte address within the
page. Therefore, when using the optional DataFlash-L page size, a total of 22 address bits are used.
For the default page size (256 bytes), the Buffer addressing is referenced in the datasheet using the conventional
terminology BFA7 - BFA0 to denote the eight address bits required to designate a byte address within the Buffer. Main
memory addressing is referenced using the terminology A17 - A0, where A17 - A8 denotes the 10 address bits required
to designate a page address, and A7 - A0 denotes the eight address bits required to designate a byte address within a
page. Therefore, when using the default page size, a total of 21 address bits are used.
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5.
Read Commands
By specifying the appropriate opcode, data can be read from the main memory or from the data buffer. The DataFlash-L
supports RapidS protocols for Mode 0 and Mode 3. Please see Section 25., "Detailed Bit-level Read Waveforms: RapidS
Mode 0/Mode 3" on page 52 for diagrams detailing the clock cycle sequences for each mode.
5.1
Continuous Array Read (Legacy Command: E8h)
By supplying an initial starting address for the main memory array, the Continuous Array Read command can be utilized
to sequentially read a continuous stream of data from the device by simply providing a clock signal; no additional
addressing information or control signals need to be provided. The DataFlash-L incorporates an internal address counter
that will automatically increment on every clock cycle, allowing one continuous read from memory to be performed
without the need for additional address sequences. To perform a Continuous Array Read using the optional DataFlash-L
page size (264-bytes), an opcode of E8h must be clocked into the device followed by three address bytes (which
comprise the 19-bit page and byte address sequence) and four dummy bytes. The first 10 bits (PA9 - PA0) of the
19-bit address sequence specify which page of the main memory array to read and the last nine bits (BA8 - BA0) of the
19-bit address sequence specify the starting byte address within the page. To perform a Continuous Array Read using
the default page size (256 bytes), the opcode E8h must be clocked into the device followed by three address bytes
(A17 - A0) and four dummy bytes. The dummy bytes that follow the address bytes are needed to initialize the read
operation. Following the dummy bytes, additional clock pulses on the SCK pin will result in data being output on the
SO (Serial Output) pin.
The CS pin must remain low during the loading of the opcode, the address bytes, the dummy bytes and the reading of
data. When the end of a page in main memory is reached during a Continuous Array Read, the device will continue
reading at the beginning of the next page with no delays incurred during the page boundary crossover (the crossover
from the end of one page to the beginning of the next page). When the last bit in the main memory array has been read,
the device will continue reading back at the beginning of the first page of memory. As with crossing over page
boundaries, no delays will be incurred when wrapping around from the end of the array to the beginning of the array.
A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The maximum
SCK frequency allowable for the Continuous Array Read is defined by the fCAR1 specification. The Continuous Array
Read bypasses the data buffer and leaves the contents of the Buffer unchanged.
Note: This command is not recommended for new designs.
5.2
Continuous Array Read (High Frequency Mode: 0Bh Opcode)
This command can be used to read the main memory array sequentially at the highest possible operating clock
frequency up to the maximum specified by fCAR1. To perform a Continuous Array Read using the optional DataFlash-L
page size (264 bytes), the CS pin must first be asserted, and then an opcode of 0Bh must be clocked into the device
followed by three address bytes and one dummy byte. The first 10 bits (PA9 - PA0) of the 19-bit address sequence
specify which page of the main memory array to read and the last nine bits (BA8 - BA0) of the 19-bit address sequence
specify the starting byte address within the page. To perform a Continuous Array Read using the default page size
(256 bytes), the opcode 0Bh must be clocked into the device followed by three address bytes (A17 - A0) and one dummy
byte. Following the dummy byte, additional clock pulses on the SCK pin will result in data being output on the SO pin.
The CS pin must remain low during the loading of the opcode, the address bytes, the dummy byte, and the reading of
data. When the end of a page in the main memory is reached during a Continuous Array Read, the device will continue
reading at the beginning of the next page with no delays incurred during the page boundary crossover (the crossover
from the end of one page to the beginning of the next page). When the last bit in the main memory array has been read,
the device will continue reading back at the beginning of the first page of memory. As with crossing over page
boundaries, no delays will be incurred when wrapping around from the end of the array to the beginning of the array.
A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The maximum
SCK frequency allowable for the Continuous Array Read is defined by the fCAR1 specification. The Continuous Array
Read bypasses the data buffer and leaves the contents of the Buffer unchanged.
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5.3
Continuous Array Read (Low Frequency Mode: 03h Opcode)
This command can be used to read the main memory array sequentially at lower clock frequencies up to maximum
specified by fCAR2. Unlike the previously described read commands, this Continuous Array Read command for lower
clock frequencies does not require the clocking in of dummy bytes after the address byte sequence. To perform a
Continuous Array Read using the optional DataFlash-L page size (264 bytes), the CS pin must first be asserted, and then
an opcode of 03h must be clocked into the device followed by three address bytes (which comprise the 24-bit page and
byte address sequence). The first 10 bits (PA9 - PA0) of the 19-bit address sequence specify which page of the main
memory array to read, and the last nine bits (BA8 - BA0) of the 19-bit address sequence specify the starting byte address
within the page. To perform a Continuous Array Read using the default page size (256 bytes), the opcode 03h must be
clocked into the device followed by three address bytes (A17 - A0). Following the address bytes, additional clock pulses
on the SCK pin will result in data being output on the SO pin.
The CS pin must remain low during the loading of the opcode, the address bytes, and the reading of data. When the end
of a page in the main memory is reached during a Continuous Array Read, the device will continue reading at the
beginning of the next page with no delays incurred during the page boundary crossover (the crossover from the end of
one page to the beginning of the next page). When the last bit in the main memory array has been read, the device will
continue reading back at the beginning of the first page of memory. As with crossing over page boundaries, no delays will
be incurred when wrapping around from the end of the array to the beginning of the array.
A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The maximum
SCK frequency allowable for the Continuous Array Read is defined by the fCAR2 specification. The Continuous Array
Read bypasses the data buffer and leaves the contents of the Buffer unchanged.
5.4
Continuous Array Read (Low Power Mode: 01h Opcode)
This command is ideal for applications that want to minimize power consumption and do not need to read the memory
array at high frequencies. Like the 03h opcode, this Continuous Array Read command allows reading the main memory
array sequentially without the need for dummy bytes to be clocked in after the address byte sequence. The memory can
be read at clock frequencies up to maximum specified by fCAR3. To perform a Continuous Array Read using the optional
DataFlash-L page size (264 bytes), the CS pin must first be asserted, and then an opcode of 01h must be clocked into
the device followed by three address bytes (which comprise the 24-bit page and byte address sequence). The first 10
bits
(PA9 - PA0) of the 19-bit address sequence specify which page of the main memory array to read and the last nine bits
(BA8 - BA0) of the 19-bit address sequence specify the starting byte address within the page. To perform a Continuous
Array Read using the default page size (256 bytes), the opcode 01h must be clocked into the device followed by three
address bytes (A17 - A0). Following the address bytes, additional clock pulses on the SCK pin will result in data being
output on the SO pin.
The CS pin must remain low during the loading of the opcode, the address bytes, and the reading of data. When the end
of a page in the main memory is reached during a Continuous Array Read, the device will continue reading at the
beginning of the next page with no delays incurred during the page boundary crossover (the crossover from the end of
one page to the beginning of the next page). When the last bit in the main memory array has been read, the device will
continue reading back at the beginning of the first page of memory. As with crossing over page boundaries, no delays will
be incurred when wrapping around from the end of the array to the beginning of the array.
A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The maximum
SCK frequency allowable for the Continuous Array Read is defined by the fCAR3 specification. The Continuous Array
Read bypasses the data buffer and leaves the contents of the Buffer unchanged.
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5.5
Main Memory Page Read
A Main Memory Page Read allows the user to read data directly from any one of the 1,024 pages in the main memory,
bypassing the data buffer and leaving the contents of the Buffer unchanged. To start a Main Memory Page Read using
the optional DataFlash-L page size (264 bytes), the CS pin must first be asserted then an opcode of D2h must be
clocked into the device followed by three address bytes (which comprise the 24-bit page and byte address sequence)
and four dummy bytes. The first 10 bits (PA9 - PA0) of the 19-bit address sequence specify which page of the main
memory array to read, and the last nine bits (BA8 - BA0) of the 19-bit address sequence specify the starting byte address
within the page. To perform a Main Memory Page Read with the default page size (256 bytes), the opcode D2h must be
clocked into the device followed by three address bytes (A17 - A0) and four dummy bytes. The first 10 bits (A17 - A8) of
the
18-bit address sequence specify which page of the main memory array to read, and the last eight bits (A7 - A0) of the
18-bit address sequence specify the starting byte address within that page. The dummy bytes that follow the address
bytes are sent to initialize the read operation. Following the dummy bytes, the additional pulses on SCK result in data
being output on the SO (Serial Output) pin.
The CS pin must remain low during the loading of the opcode, the address bytes, the dummy bytes, and the reading of
data. Unlike the Continuous Array Read command, when the end of a page in main memory is reached, the device will
continue reading back at the beginning of the same page rather than the beginning of the next page.
A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The maximum
SCK frequency allowable for the Main Memory Page Read is defined by the fSCK specification. The Main Memory Page
Read bypasses the data buffer and leaves the contents of the Buffer unchanged.
5.6
Buffer Read
The data buffer can be accessed independently from the main memory array, and utilizing the Buffer Read command
allows data to be sequentially read directly from the Buffer. Two opcodes, D4h or D1h, can be used for the Buffer Read
command. The use of each opcode depends on the maximum SCK frequency that will be used to read data from the
Buffer. The D4h opcode can be used at any SCK frequency up to the maximum specified by fCAR while the D1h opcode
can be used for lower frequency read operations up to the maximum specified by fCAR2
.
To perform a Buffer Read using the optional DataFlash-L buffer size (264 bytes), the opcode must be clocked into the
device followed by three address bytes comprised of 15 dummy bits and nine buffer address bits (BFA8 -BFA0). To
perform a Buffer Read using the default buffer size (256 bytes), the opcode must be clocked into the device followed by
three address bytes comprised of 16 dummy bits and eight address bits (A7 - A0). Following the address bytes, one
dummy byte must be clocked into the device to initialize the read operation if using opcode D4h. The CS must remain low
during the loading of the opcode, the address bytes, the dummy byte (for opcode D4h only), and the reading of data.
When the end of a buffer is reached, the device will continue reading back at the beginning of the Buffer. A
low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO).
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6.
Program and Erase Commands
6.1
Buffer Write
Utilizing the Buffer Write command allows data clocked in from the SI pin to be written directly into the data buffer.
To load data into the Buffer using the optional DataFlash-L buffer size (264 bytes), an opcode of 84h must be clocked
into the device followed by three address bytes comprised of 15 dummy bits and nine buffer address bits (BFA8 - BFA0).
The nine buffer address bits specify the first byte in the Buffer to be written.
To load data into the Buffer using the default buffer size (256 bytes), an opcode of 84h must be clocked into the device
followed by 16 dummy bits and eight address bits (A7 - A0). The eight address bits specify the first byte in the Buffer to
be written.
After the last address byte has been clocked into the device, data can then be clocked in on subsequent clock cycles. If
the end of the data buffer is reached, the device will wrap around back to the beginning of the Buffer. Data will continue
to be loaded into the Buffer until a low-to-high transition is detected on the CS pin.
6.2
Buffer to Main Memory Page Program with Built-In Erase
The Buffer to Main Memory Page Program with Built-In Erase command allows data that is stored in the Buffer to be
written into an erased or programmed page in the main memory array. It is not necessary to pre-erase the page in main
memory to be written because this command will automatically erase the selected page prior to the program cycle.
To perform a Buffer to Main Memory Page Program with Built-In Erase using the optional DataFlash-L page size
(264 bytes), an opcode of 83h must be clocked into the device followed by three address bytes comprised of five dummy
bits,10 page address bits (PA9 - PA0) that specify the page in the main memory to be written, and nine dummy bits.
To perform a Buffer to Main Memory Page Program with Built-In Erase using the default page size (256 bytes), an
opcode of 83h must be clocked into the device followed by three address bytes comprised of six dummy bits, 10 page
address bits (A17 - A8) that specify the page in the main memory to be written, and eight dummy bits.
When a low-to-high transition occurs on the CS pin, the device will first erase the selected page in main memory
(the erased state is a Logic 1) and then program the data stored in the Buffer into that same page in main memory. Both
the erasing and the programming of the page are internally self-timed and should take place in a maximum time of tEP
During this time, the RDY/BUSY bit in the Status Register will indicate that the device is busy.
.
The device also incorporates intelligent erase and program algorithms that can detect when a byte location fails to erase
or program properly. If an erase or programming error arises, it will be indicated by the EPE bit in the Status Register.
6.3
Buffer to Main Memory Page Program without Built-In Erase
The Buffer to Main Memory Page Program without Built-In Erase command allows data that is stored in the Buffer to be
written into a pre-erased page in the main memory array. It is necessary that the page in main memory to be written be
previously erased in order to avoid programming errors.
To perform a Buffer to Main Memory Page Program without Built-In Erase using the optional DataFlash-L page size
(264 bytes), an opcode of 88h must be clocked into the device followed by three address bytes comprised of five dummy
bits,10 page address bits (PA9 - PA0) that specify the page in the main memory to be written, and nine dummy bits.
To perform a Buffer to Main Memory Page Program using the default page size (256 bytes), an opcode 88h must be
clocked into the device followed by three address bytes comprised of six dummy bits, 10 page address bits (A17 - A8)
that specify the page in the main memory to be written, and eight dummy bits.
When a low-to-high transition occurs on the CS pin, the device will program the data stored in the Buffer into the
specified page in the main memory. The page in main memory that is being programmed must have been previously
erased using one of the erase commands (Page Erase, Block Erase, Sector Erase, or Chip Erase). The programming of
the page is internally self-timed and should take place in a maximum time of tP. During this time, the RDY/BUSY bit in the
Status Register will indicate that the device is busy.
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The device also incorporates an intelligent programming algorithm that can detect when a byte location fails to program
properly. If a programming error arises, it will be indicated by the EPE bit in the Status Register.
6.4
Main Memory Page Program through Buffer with Built-In Erase
The Main Memory Page Program through Buffer with Built-In Erase command combines the Buffer Write and Buffer to
Main Memory Page Program with Built-In Erase operations into a single operation to help simplify application firmware
development. With the Main Memory Page Program through Buffer with Built-In Erase command, data is first clocked
into the Buffer, the addressed page in memory is then automatically erased, and then the contents of the Buffer are
programmed into the just-erased main memory page.
To perform a Main Memory Page Program through Buffer using the optional DataFlash-L page size (264 bytes), an
opcode of 82h must first be clocked into the device followed by three address bytes comprised of five dummy bits,
10 page address bits (PA9 - PA0) that specify the page in the main memory to be written, and nine buffer address bits
(BFA8 - BFA0) that select the first byte in the Buffer to be written.
To perform a Main Memory Page Program through Buffer using the default page size (256 bytes), an opcode of 82h must
first be clocked into the device followed by three address bytes comprised of six dummy bits, 10 page address bits
(A17 - A8) that specify the page in the main memory to be written, and eight address bits (A7 - A0) that selects the first
byte in the Buffer to be written.
After all address bytes have been clocked in, the device will take data from the input pin (SI) and store it in the Buffer. If
the end of the Buffer is reached, the device will wrap around back to the beginning of the Buffer. When there is a
low-to-high transition on the CS pin, the device will first erase the selected page in main memory (the erased state is a
Logic 1) and then program the data stored in the Buffer into that main memory page. Both the erasing and the
programming of the page are internally self-timed and should take place in a maximum time of tEP. During this time, the
RDY/BUSY bit in the Status Register will indicate that the device is busy.
The device also incorporates intelligent erase and programming algorithms that can detect when a byte location fails to
erase or program properly. If an erase or program error arises, it will be indicated by the EPE bit in the Status Register.
6.5
Main Memory Byte/Page Program through Buffer without Built-In Erase
The Main Memory Byte/Page Program through the Buffer without Built-In Erase combines both the Buffer Write and
Buffer to Main Memory Program without Built-In Erase operations to allow any number of bytes (1 to 256/264 bytes) to be
programmed directly into previously erased locations in the main memory array. With the Main Memory Byte/Page
Program through Buffer without Built-In Erase command, data is first clocked into Buffer, and then only the bytes clocked
into the Buffer are programmed into the pre-erased byte locations in main memory. Multiple bytes up to the page size can
be entered with one command sequence.
To perform a Main Memory Byte/Page Program through the Buffer using the optional DataFlash-L page size (264 bytes),
an opcode of 02h must first be clocked into the device followed by three address bytes comprised of five dummy bits,
10 page address bits (PA9 - PA0) that specify the page in the main memory to be written, and nine buffer address bits
(BFA8 - BFA0) that select the first byte in the Buffer to be written. After all address bytes are clocked in, the device will
take data from the input pin (SI) and store it in the Buffer. Any number of bytes (1 to 264) can be entered. If the end of the
Buffer is reached, then the device will wrap around back to the beginning of the Buffer.
To perform a Main Memory Byte/Page Program through the Buffer using the default page size (256 bytes), an opcode of
02h must first be clocked into the device followed by three address bytes comprised of six dummy bits, 10 page address
bits (PA9 - PA0) that specify the page in the main memory to be written, and eight address bits (A7 - A0) that selects the
first byte in the Buffer to be written. After all address bytes are clocked in, the device will take data from the input pin (SI)
and store it in the Buffer. Any number of bytes (1 to 256) can be entered. If the end of the Buffer is reached, then the
device will wrap around back to the beginning of the Buffer. When using the default page size, the page and buffer
address bits correspond to an 18-bit logical address (A17-A0) in the main memory.
After all data bytes have been clocked into the device, a low-to-high transition on the CS pin will start the program
operation in which the device will program the data stored in the Buffer into the main memory array. Only the data bytes
that were clocked into the device will be programmed into the main memory.
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Example: If only two data bytes were clocked into the device, then only two bytes will be programmed into main
memory and the remaining bytes in the memory page will remain in their previous state.
The CS pin must be deasserted on a byte boundary (multiples of eight bits); otherwise the operation will be aborted and
no data will be programmed. The programming of the data bytes is internally self-timed and should take place in a
maximum time of tP (the program time will be a multiple of the tBP time depending on the number of bytes being
programmed). During this time, the RDY/BUSY bit in the Status Register will indicate that the device is busy.
The device also incorporates an intelligent programming algorithm that can detect when a byte location fails to program
properly. If a programming error arises, it will be indicated by the EPE bit in the Status Register.
6.6
Page Erase
The Page Erase command can be used to individually erase any page in the main memory array allowing the Buffer to
Main Memory Page Program without Built-In Erase command or the Main Memory Byte/Page Program through Buffer
command to be utilized at a later time.
To perform a Page Erase with the optional DataFlash-L page size (264 bytes), an opcode of 81h must be clocked into the
device followed by three address bytes comprised of five dummy bits, 10 page address bits (PA9 - PA0) that specify the
page in the main memory to be erased, and nine dummy bits.
To perform a Page Erase with the default page size (256 bytes), an opcode of 81h must be clocked into the device
followed by three address bytes comprised of six dummy bits, 10 page address bits (A17 - A8) that specify the page in
the main memory to be erased, and eight dummy bits.
When a low-to-high transition occurs on the CS pin, the device will erase the selected page (the erased state is a
Logic 1). The erase operation is internally self-timed and should take place in a maximum time of tPE. During this time, the
RDY/BUSY bit in the Status Register will indicate that the device is busy.
The device also incorporates an intelligent erase algorithm that can detect when a byte location fails to erase properly. If
an erase error arises, it will be indicated by the EPE bit in the Status Register.
6.7
Block Erase
The Block Erase command can be used to erase a block of eight pages at one time. This command is useful when
needing to pre-erase larger amounts of memory and is more efficient than issuing eight separate Page Erase
commands.
To perform a Block Erase with the optional DataFlash-L page size (264 bytes), an opcode of 50h must be clocked into
the device followed by three address bytes comprised of five dummy bits, seven page address bits (PA9 - PA3), and
12 dummy bits. The seven page address bits are used to specify which block of eight pages is to be erased.
To perform a Block Erase with the default page size (256 bytes), an opcode of 50h must be clocked into the device
followed by three address bytes comprised of six dummy bits, seven page address bits (A17 - A11), and 11 dummy bits.
The seven page address bits are used to specify which block of eight pages is to be erased.
When a low-to-high transition occurs on the CS pin, the device will erase the selected block of eight pages. The erase
operation is internally self-timed and should take place in a maximum time of tBE. During this time, the RDY/BUSY bit in
the Status Register will indicate that the device is busy.
The device also incorporates an intelligent erase algorithm that can detect when a byte location fails to erase properly. If
an erase error arises, it will be indicated by the EPE bit in the Status Register.
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Table 6-1. Block Erase Addressing
PA9/A17 PA8/A16 PA7/A15 PA6/A14 PA5/A13 PA4/A12 PA3/A11 PA2/A10 PA1/A9
PA0/A8
Block
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
1
0
1
X
X
X
X
X
X
X
X
X
X
X
X
0
1
2
3
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
1
1
0
1
0
1
X
X
X
X
X
X
X
X
X
X
X
X
124
125
126
127
6.8
Sector Erase
The Sector Erase command can be used to individually erase any sector in the main memory.
The main memory array is comprised of nine sectors, and only one sector can be erased at a time. To perform an erase
of Sector 0a or Sector 0b with the optional DataFlash-L page size (264 bytes), an opcode of 7Ch must be clocked into the
device followed by three address bytes comprised of five dummy bits, seven page address bits (PA9 - PA3), and
12 dummy bits. To perform a Sector 1-7 erase, an opcode of 7Ch must be clocked into the device followed by three
address bytes comprised of five dummy bits, three page address bits (PA9 - PA7), and 16 dummy bits.
To perform a Sector 0a or Sector 0b erase with the default page size (256 bytes), an opcode of 7Ch must be clocked into
the device followed by three address bytes comprised of six dummy bits, seven page address bits (A17 - A11), and
11 dummy bits. To perform a Sector 1-7 erase, an opcode of 7Ch must be clocked into the device followed by six dummy
bits, three page address bits (A17 - A15), and 15 dummy bits.
The page address bits are used to specify any valid address location within the sector is to be erased. When a
low-to-high transition occurs on the CS pin, the device will erase the selected sector. The erase operation is internally
self-timed and should take place in a maximum time of tSE. During this time, the RDY/BUSY bit in the Status Register will
indicate that the device is busy.
The device also incorporates an intelligent erase algorithm that can detect when a byte location fails to erase properly. If
an erase error arises, it will be indicated by the EPE bit in the Status Register.
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Table 6-2. Sector Erase Addressing
PA9/A17 PA8/A16 PA7/A15 PA6/A14 PA5/A13 PA4/A12 PA3/A11 PA2/A10 PA1/A9
PA0/A8
Sector
0
0
0
0
0
0
0
0
1
0
0
X
0
0
X
0
0
0
1
X
X
X
X
X
X
X
X
X
X
0a
0b
1
X
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
1
1
1
0
1
1
1
0
1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
5
6
7
6.9
Chip Erase
The Chip Erase command allows the entire main memory array to be erased at one time.
To execute the Chip Erase command, a 4-byte command sequence of C7h, 94h, 80h, and 9Ah must be clocked into the
device. Since the entire memory array is to be erased, no address bytes need to be clocked into the device and any data
clocked in after the opcode will be ignored. After the last bit of the opcode sequence has been clocked in, the CS pin
must be deasserted to start the erase process. The erase operation is internally self-timed and should take place in a
time of tCE. During this time, the RDY/BUSY bit in the Status Register will indicate that the device is busy.
The Chip Erase command will not affect sectors that are protected or locked down; the contents of those sectors will
remain unchanged. Only those sectors that are not protected or locked down will be erased.
The WP pin can be asserted while the device is erasing, but protection will not be activated until the internal erase cycle
completes.
The device also incorporates an intelligent erase algorithm that can detect when a byte location fails to erase properly. If
an erase error arises, it will be indicated by the EPE bit in the Status Register.
Table 6-3. Chip Erase Command
Command
Byte 1
Byte 2
Byte 3
Byte 4
Chip Erase
C7h
94h
80h
9Ah
Figure 6-1. Chip Erase
CS
C7h
94h
80h
9Ah
Each transition represents eight bits
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6.10 Read-Modify-Write
A completely self-contained read-modify-write operation can be performed to reprogram any number of sequential bytes
in a page in the main memory array without affecting the rest of the bytes in the same page. This command allows the
device to easily emulate an EEPROM by providing a method to modify a single byte or more in the main memory in a
single operation, without the need for pre-erasing the memory or the need for any external RAM buffers. The
Read-Modify-Write command is essentially a combination of the Main Memory Page to Buffer Transfer, Buffer Write, and
Buffer to Main Memory Page Program with Built-in Erase commands.
To perform a Read-Modify-Write using the optional DataFlash-L page size (264 bytes), an opcode of 58h for Buffer 1
must be clocked into the device followed by three address bytes comprised of five dummy bits, 10 page address bits
(PA9 - PA0) that specify the page in the main memory to be written and nine byte address bits (BA8-BA0) that designate
the starting byte address within the page to reprogram.
To perform a Read-Modify-Write using the default page size (256 bytes), an opcode of 58h for Buffer 1 must be clocked
into the device followed by three address bytes comprised of six dummy bits, 10 page address bits (A17 - A8) that
specify the page in the main memory to be written and eight byte address bits (A7-A0) that designate the starting byte
address within the page to reprogram.
After the address bytes have been clocked in, any number of sequential data bytes from one to 256/264 bytes can be
clocked into the device. If the end of the buffer is reached when clocking in the data, then the device will wrap around
back to the beginning of the buffer. After all data bytes have been clocked into the device, a low-to-high transition on the
CS pin will start the self-contained, internal read-modify-write operation. Only the data bytes that were clocked into the
device will be reprogrammed in the main memory.
Example: If only one data byte was clocked into the device, then only one byte in main memory will be reprogrammed
and the remaining bytes in the main memory page will remain in their previous state.
The CS pin must be deasserted on a byte boundary (multiples of eight bits); otherwise, the operation will be aborted and
no data will be programmed. The reprogramming of the data bytes is internally self-timed and should take place in a
maximum time of tP. During this time, the RDY/BUSY bit in the Status Register will indicate that the device is busy.
The device also incorporates an intelligent erase and programming algorithm that can detect when a byte location fails to
erase or program properly. If an erase or program error arises, it will be indicated by the EPE bit in the Status Register.
Note: The Read-Modify-Write command uses the same opcodes as the Auto Page Rewrite command. If no data bytes
are clocked into the device, then the device will perform an Auto Page Rewrite operation. See the Auto Page
Rewrite command description on page 22 for more details.
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7.
Sector Protection
Two protection methods, hardware and software controlled, are provided for protection against inadvertent or erroneous
program and erase cycles. The software controlled method relies on the use of software commands to enable and
disable sector protection while the hardware controlled method employs the use of the Write Protect (WP) pin. The
selection of which sectors that are to be protected or unprotected against program and erase operations is specified in
the nonvolatile Sector Protection Register. The status of whether or not sector protection has been enabled or disabled
by either the software or the hardware controlled methods can be determined by checking the Status Register.
7.1
Software Sector Protection
Software controlled protection is useful in applications in which the WP pin is not or cannot be controlled by a host
processor. In such instances, the WP pin may be left floating (the WP pin is internally pulled high) and sector protection
can be controlled using the Enable Sector Protection and Disable Sector Protection commands.
If the device is power cycled, then the software controlled protection will be disabled. Once the device is powered up, the
Enable Sector Protection command should be reissued if sector protection is desired and if the WP pin is not used.
7.1.1 Enable Sector Protection
Sectors specified for protection in the Sector Protection Register can be protected from program and erase operations by
issuing the Enable Sector Protection command. To enable the sector protection, a 4-byte command sequence of
3Dh, 2Ah, 7Fh, and A9h must be clocked into the device. After the last bit of the opcode sequence has been clocked in,
the CS pin must be deasserted to enable the Sector Protection.
Table 7-1. Enable Sector Protection Command
Command
Byte 1
Byte 2
Byte 3
Byte 4
Enable Sector Protection
3Dh
2Ah
7Fh
A9h
Figure 7-1. Enable Sector Protection
CS
A9h
3Dh
2Ah
7Fh
SI
Each transition represents eight bits
7.1.2 Disable Sector Protection
To disable the sector protection, a 4-byte command sequence of 3Dh, 2Ah, 7Fh, and 9Ah must be clocked into the
device. After the last bit of the opcode sequence has been clocked in, the CS pin must be deasserted to disable the
sector protection.
Table 7-2. Disable Sector Protection Command
Command
Byte 1
Byte 2
Byte 3
Byte 4
Disable Sector Protection
3Dh
2Ah
7Fh
9Ah
Figure 7-2. Disable Sector Protection
CS
3Dh
2Ah
7Fh
9Ah
SI
Each transition represents eight bits
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7.2
Hardware Controlled Protection
Sectors specified for protection in the Sector Protection Register and the Sector Protection Register itself can be
protected from program and erase operations by asserting the WP pin and keeping the pin in its asserted state. The
Sector Protection Register and any sector specified for protection cannot be erased or programmed as long as the WP
pin is asserted. In order to modify the Sector Protection Register, the WP pin must be deasserted. If the WP pin is
permanently connected to GND, then the contents of the Sector Protection Register cannot be changed. If the WP pin is
deasserted or permanently connected to VCC, then the contents of the Sector Protection Register can be modified.
The WP pin will override the software controlled protection method but only for protecting the sectors.
Example: If the sectors were not previously protected by the Enable Sector Protection command, then simply
asserting the WP pin would enable the sector protection within the maximum specified tWPE time. When the
WP pin is deasserted, however, the sector protection would no longer be enabled (after the maximum
specified tWPD time) as long as the Enable Sector Protection command was not issued while the WP pin was
asserted. If the Enable Sector Protection command was issued before or while the WP pin was asserted,
then simply deasserting the WP pin would not disable the sector protection. In this case, the Disable Sector
Protection command would need to be issued while the WP pin is deasserted to disable the sector
protection. The Disable Sector Protection command is also ignored whenever the WP pin is asserted.
A noise filter is incorporated to help protect against spurious noise that my inadvertently assert or deassert the WP pin.
Figure 7-3 and Table 7-3 detail the sector protection status for various scenarios of the WP pin, the Enable Sector
Protection command, and the Disable Sector Protection command.
Figure 7-3. WP Pin and Protection Status
1
2
3
WP
Table 7-3. WP Pin and Protection Status
Time
Sector
Protection
Status
Sector
Protection
Register
Disable Sector
Protection Command
Period
WP Pin
Enable Sector Protection Command
Command Not Issued Previously
X
Disabled
Disabled
Enabled
Enabled
Enabled
Disabled
Enabled
Read/Write
Read/Write
Read/Write
Read
1
2
3
High
—
Issue Command
Issue Command
—
Low
X
X
Command Issued During Period 1 or 2
Not Issued Yet
Issue Command
—
Read/Write
Read/Write
Read/Write
High
—
Issue Command
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7.3
Sector Protection Register
The nonvolatile Sector Protection Register specifies which sectors are to be protected or unprotected with either the
software or hardware controlled protection methods. The Sector Protection Register contains eight bytes of data, of
which byte locations 0 through 7 contain values that specify whether Sectors 0 through 7 will be protected or
unprotected. The Sector Protection Register is user modifiable and must be erased before it can be reprogrammed.
Table 7-4 illustrates the format of the Sector Protection Register.
Table 7-4. Sector Protection Register
Sector Number
Protected
0 (0a, 0b)
1 to 7
FFh
See Table 7-5
Unprotected
00h
Note: 1. The default values for bytes 0 through 7 are 00h when shipped from Adesto.
Table 7-5. Sector 0 (0a, 0b) Sector Protection Register Byte Value
Bit 7:6
Bit 5:4
Bit 3:2
Bit 1:0
Sector 0a
(Page 0-7)
Sector 0b
(Page 8-127)
N/A
XX
XX
XX
XX
N/A
XX
XX
XX
XX
Data Value
Sectors 0a and 0b Unprotected
Protect Sector 0a
00
11
00
11
00
00
11
11
0Xh
CXh
3Xh
FXh
Protect Sector 0b
Protect Sectors 0a and 0b
Note: 1. X = Don’t care
7.3.1 Erase Sector Protection Register
In order to modify and change the values of the Sector Protection Register, it must first be erased using the Erase Sector
Protection Register command.
To erase the Sector Protection Register, a 4-byte command sequence of 3Dh, 2Ah, 7Fh, and CFh must be clocked into
the device. After the last bit of the opcode sequence has been clocked in, the CS pin must be deasserted to initiate the
internally self-timed erase cycle. The erasing of the Sector Protection Register should take place in a maximum time of
tPE. During this time, the RDY/BUSY bit in the Status Register will indicate that the device is busy. If the device is
powered-down before the completion of the erase cycle, then the contents of the Sector Protection Register cannot be
guaranteed.
The Sector Protection Register can be erased with sector protection enabled or disabled. Since the erased state (FFh) of
each byte in the Sector Protection Register is used to indicate that a sector is specified for protection, leaving the sector
protection enabled during the erasing of the register allows the protection scheme to be more effective in the prevention
of accidental programming or erasing of the device. If for some reason an erroneous program or erase command is sent
to the device immediately after erasing the Sector Protection Register and before the register can be reprogrammed,
then the erroneous program or erase command will not be processed because all sectors would be protected.
Table 7-6. Erase Sector Protection Register Command
Command
Byte 1
Byte 2
Byte 3
Byte 4
Erase Sector Protection Register
3Dh
2Ah
7Fh
CFh
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Figure 7-4. Erase Sector Protection Register
CS
SI
3Dh
2Ah
7Fh
CFh
Each transition represents eight bits
7.3.2 Program Sector Protection Register
Once the Sector Protection Register has been erased, it can be reprogrammed using the Program Sector Protection
Register command.
To program the Sector Protection Register, a 4-byte command sequence of 3Dh, 2Ah, 7Fh, and FCh must be clocked
into the device followed by eight bytes of data corresponding to Sectors 0 through 7. After the last bit of the opcode
sequence and data have been clocked in, the CS pin must be deasserted to initiate the internally self-timed program
cycle. The programming of the Sector Protection Register should take place in a maximum time of tP. During this time,
the RDY/BUSY bit in the Status Register will indicate that the device is busy. If the device is powered-down before the
completion of the erase cycle, then the contents of the Sector Protection Register cannot be guaranteed.
If the proper number of data bytes is not clocked in before the CS pin is deasserted, then the protection status of the
sectors corresponding to the bytes not clocked in cannot be guaranteed.
Example: If only the first two bytes are clocked in instead of the complete eight bytes, then the protection status of the
last six sectors cannot be guaranteed. Furthermore, if more than eight bytes of data is clocked into the
device, then the data will wrap back around to the beginning of the register. For instance, if nine bytes of
data are clocked in, then the ninth byte will be stored at byte location 0 of the Sector Protection Register.
The data bytes clocked into the Sector Protection Register need to be valid values (0Xh, 3Xh, CXh, and FXh for Sector
0a or Sector 0b, and 00h or FFh for other sectors) in order for the protection to function correctly. If a non-valid value is
clocked into a byte location of the Sector Protection Register, then the protection status of the sector corresponding to
that byte location cannot be guaranteed.
Example: If a value of 17h is clocked into byte location 2 of the Sector Protection Register, then the protection status
of Sector 2 cannot be guaranteed.
The Sector Protection Register can be reprogrammed while the sector protection is enabled or disabled. Being able to
reprogram the Sector Protection Register with the sector protection enabled allows the user to temporarily disable the
sector protection to an individual sector rather than disabling sector protection completely.
The Program Sector Protection Register command utilizes the internal buffer for processing. Therefore, the contents of
the Buffer will be altered from its previous state when this command is issued.
Table 7-7. Program Sector Protection Register Command
Command
Byte 1
Byte 2
Byte 3
Byte 4
Program Sector Protection Register
3Dh
2Ah
7Fh
FCh
Figure 7-5. Program Sector Protection Register
CS
Data Byte
n
Data Byte
n + 1
Data Byte
n + 7
3Dh
2Ah
7Fh
FCh
SI
Each transition represents eight bits
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7.3.3 Read Sector Protection Register
To read the Sector Protection Register, an opcode of 32h and three dummy bytes must be clocked into the device. After
the last bit of the opcode and dummy bytes have been clocked in, any additional clock pulses on the SCK pin will result
in the Sector Protection Register contents being output on the SO pin. The first byte (byte location 0) corresponds to
Sector 0 (0a and 0b), the second byte corresponds to Sector 1, and the last byte (byte location 7) corresponds to
Sector 7. Once the last byte of the Sector Protection Register has been clocked out, any additional clock pulses will result
in undefined data being output on the SO pin. The CS pin must be deasserted to terminate the Read Sector Protection
Register operation and put the output into a high-impedance state.
Table 7-8. Read Sector Protection Register Command
Command
Byte 1
Byte 2
Byte 3
Byte 4
Read Sector Protection Register
32h
XXh
XXh
XXh
Note: 1. XX = Dummy byte
Figure 7-6. Read Sector Protection Register
CS
32h
XX
XX
XX
SI
Data
n
Data
n + 1
Data
n + 7
SO
Each transition represents eight bits
7.3.4 About the Sector Protection Register
The Sector Protection Register is subject to a limit of 10,000 erase/program cycles. Users are encouraged to carefully
evaluate the number of times the Sector Protection Register will be modified during the course of the application’s life
cycle. If the application requires that the Security Protection Register be modified more than the specified limit of 10,000
cycles because the application needs to temporarily unprotect individual sectors (sector protection remains enabled
while the Sector Protection Register is reprogrammed), then the application will need to limit this practice. Instead, a
combination of temporarily unprotecting individual sectors along with disabling sector protection completely will need to
be implemented by the application to ensure that the limit of 10,000 cycles is not exceeded.
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8.
Security Features
8.1
Security Register
The device contains a specialized Security Register that can be used for purposes such as unique device serialization or
locked key storage. The register is comprised of a total of 128 bytes (byte locations 0 through 127). All 128 bytes of the
Security Register are factory programmed by Adesto and will contain a unique value for each device. The factory
programmed data is fixed and cannot be changed.
Table 8-1. Security Register
Security Register Byte Number
0
· · ·
127
Data Type
Factory Programmed by Adesto
8.1.1 Reading the Security Register
To read the Security Register, an opcode of 77h and three dummy bytes must be clocked into the device. After the last
dummy bit has been clocked in, the contents of the Security Register can be clocked out on the SO pin. After the last
byte of the Security Register has been read, additional pulses on the SCK pin will result in undefined data being output
on the SO pin.
Deasserting the CS pin will terminate the Read Security Register operation and put the SO pin into a high-impedance
state.
Figure 8-1. Read Security Register
CS
SI
77h
XX
XX
XX
Data
n
Data
n + 1
Data
n + x
SO
Each transition represents eight bits
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9.
Additional Commands
9.1
Main Memory Page to Buffer Transfer
A page of data can be transferred from the main memory to the Buffer. To transfer a page of data using the optional
DataFlash-L page size (264 bytes), an opcode of 53h must be clocked into the device followed by three address bytes
comprised of five dummy bits, 10 page address bits (PA9 - PA0) which specify the page in main memory to be
transferred, and nine dummy bits. To transfer a page of data using the default page size (256 bytes), an opcode of 53h
must be clocked into the device followed by three address bytes comprised of six dummy bits, 10 page address bits
(A17 - A8) which specify the page in the main memory to be transferred, and eight dummy bits.
The CS pin must be low while toggling the SCK pin to load the opcode and the three address bytes from the input
pin (SI). The transfer of the page of data from the main memory to the Buffer will begin when the CS pin transitions from
a low to a high state. During the page transfer time (tXFR), the RDY/BUSY bit in the Status Register can be read to
determine whether or not the transfer has been completed.
9.2
Main Memory Page to Buffer Compare
A page of data in main memory can be compared to the data in the Buffer as a method to ensure that data was
successfully programmed after a Buffer to Main Memory Page Program command. To compare a page of data with the
optional DataFlash-L page size (264 bytes), an opcode of 60h must be clocked into the device followed by three address
bytes comprised of five dummy bits, 10 page address bits (PA9 - PA0) which specify the page in the main memory to be
compared to the Buffer, and nine dummy bits. To compare a page of data with the default page size (256 bytes), an
opcode of 60h must be clocked into the device followed by three address bytes comprised of six dummy bits, 10 page
address bits (A17 - A8) which specify the page in the main memory to be compared to the Buffer, and eight dummy bits.
The CS pin must be low while toggling the SCK pin to load the opcode and the address bytes from the input pin (SI). On
the low-to-high transition of the CS pin, the data bytes in the selected Main Memory Page will be compared with the data
bytes in the Buffer. During the compare time (tCOMP), the RDY/BUSY bit in the Status Register will indicate that the part is
busy. On completion of the compare operation, bit 6 of the Status Register will be updated with the result of the compare.
9.3
Auto Page Rewrite
This command only needs to be used if the possibility exists that static (non-changing) data may be stored in a page or
pages of a sector and the other pages of the same sector are erased and programmed a large number of times.
Applications that modify data in a random fashion within a sector may fall into this category. To preserve data integrity of
a sector, each page within a sector must be updated/rewritten at least once within every 50,000 cumulative page
erase/program operations within that sector. The Auto Page Rewrite command provides a simple and efficient method to
“refresh” a page in the main memory array in a single operation.
The Auto Page Rewrite command is a combination of the Main Memory Page to Buffer Transfer and Buffer to Main
Memory Page Program with Built-In Erase commands. With the Auto Page Rewrite command, a page of data is first
transferred from the main memory to the Buffer and then the same data is programmed back into the same page of main
memory, essentially “refreshing” the contents of that page. To start the Auto Page Rewrite operation with the optional
DataFlash-L page size (264 bytes), a 1-byte opcode, 58h must be clocked into the device followed by three address
bytes comprised of five dummy bits, 10 page address bits (PA9-PA0) that specify the page in main memory to be
rewritten, and nine dummy bits.
To initiate an Auto Page Rewrite with the a default page size (256 bytes), the opcode 58h must be clocked into the device
followed by three address bytes consisting of six dummy bits, 10 page address bits (A17 - A8) that specify the page in the
main memory that is to be rewritten, and eight dummy bits. When a low-to-high transition occurs on the CS pin, the part
will first transfer data from the page in main memory to the Buffer and then program the data from the Buffer back into
same page of main memory. The operation is internally self-timed and should take place in a maximum time of tEP
During this time, the RDY/BUSY Status Register will indicate that the part is busy.
.
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If a sector is programmed or reprogrammed sequentially page by page and the possibility does not exist that there will be
a page or pages of static data, then the programming algorithm shown in Figure 26-1 on page 56 is recommended;
otherwise, if there is a chance that there may be a page or pages of a sector that will contain static data, then the
programming algorithm shown in Figure 26-2 on page 57 is recommended.
Please contact Adesto for availability of devices that are specified to exceed the 50,000 cycle cumulative limit.
Note: The Auto Page Rewrite command uses the same opcodes as the Read-Modify-Write command. If data bytes
are clocked into the device, then the device will perform a Read-Modify-Write operation. See the Read-Modify-
Write command description on page 15 for more details.
9.4
Status Register Read
The 2-byte Status Register can be used to determine the device's ready/busy status, page size, a Main Memory Page to
Buffer Compare operation result, the sector protection status, erase/program error status, and the device density. The
Status Register can be read at any time, including during an internally self-timed program or erase operation.
To read the Status Register, the CS pin must first be asserted and then the opcode D7h must be clocked into the device.
After the opcode has been clocked in, the device will begin outputting Status Register data on the SO pin during every
subsequent clock cycle. After the second byte of the Status Register has been clocked out, the sequence will repeat
itself, starting again with the first byte of the Status Register, as long as the CS pin remains asserted and the clock pin is
being pulsed. The data in the Status Register is constantly being updated, so each repeating sequence may output new
data. The RDY/BUSY status is available for both bytes of the Status Register and is updated for each byte.
Deasserting the CS pin will terminate the Status Register Read operation and put the SO pin into a high-impedance
state. The CS pin can be deasserted at any time and does not require that a full byte of data be read.
Table 9-1. Status Register Format – Byte 1
Type(1)
Bit Name
Description
0
1
0
1
Device is busy with an internal operation.
7
6
RDY/BUSY Ready/Busy Status
R
Device is ready.
Main memory page data matches buffer data.
Main memory page data does not match buffer data.
COMP
Compare Result
R
R
R
5:2 DENSITY Density Code
Sector Protection
0101 2-Mbit
0
1
Sector protection is disabled.
1
PROTECT
Status
Sector protection is enabled.
Device is configured for optional DataFlash-L page size (264
bytes).
0
1
Page Size
Configuration
0
PAGE SIZE
R
Device is configured for default page size (256 bytes).
Note: 1. R = Readable only
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Table 9-2. Status Register Format – Byte 2
Bit Name
Type(1)
Description
0
1
x
0
1
x
x
x
x
x
Device is busy with an internal operation.
7
6
5
RDY/BUSY Ready/Busy Status
R
R
R
Device is ready.
RES
EPE
Reserved for Future Use
Erase/Program Error
Reserved for future use.
Erase or program operation was successful.
Erase or program error detected.
Reserved for future use.
Reserved for future use.
Reserved for future use.
Reserved for future use.
Reserved for future use.
4
3
2
1
0
RES
RES
RES
RES
RES
Reserved for Future Use
Reserved for Future Use
Reserved for Future Use
Reserved for Future Use
Reserved for Future Use
R
R
R
R
R
Note: 1. R = Readable only
2. x = Don’t care. Can be “0” or “1”.
9.4.1 RDY/BUSY Bit
The RDY/BUSY bit is used to determine whether or not an internal operation, such as a program or erase, is in progress.
To poll the RDY/BUSY bit to detect the completion of an internally timed operation, new Status Register data must be
continually clocked out of the device until the state of the RDY/BUSY bit changes from a Logic 0 to a Logic 1 to indicate
completion.
9.4.2 COMP Bit
The result of the most recent Main Memory Page to Buffer Compare operation is indicated using the COMP bit. If the
COMP bit is a Logic 1, then at least one bit of the data in the Main Memory Page does not match the data in the Buffer.
9.4.3 DENSITY Bits
The device density is indicated using the DENSITY bits. For the AT25PE20, the four bit binary value is 0101. The
decimal value of these four binary bits does not actually equate to the device density; the four bits represent a
combinational code relating to differing densities of DataFlash-L devices. The DENSITY bits are not the same as the
density code indicated in the JEDEC Device ID information. The DENSITY bits are provided only for backward
compatibility to older generation DataFlash-L devices.
9.4.4 PROTECT Bit
The PROTECT bit provides information to the user on whether or not the sector protection has been enabled or disabled,
either by the software-controlled method or the hardware-controlled method.
9.4.5 PAGE SIZE Bit
The PAGE SIZE bit indicates whether the Buffer size and the page size of the main memory array is configured for the
default page size (256 bytes) or the optional DataFlash-L page size (264 bytes).
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9.4.6 EPE Bit
The EPE bit indicates whether the last erase or program operation completed successfully or not. If at least one byte
during the erase or program operation did not erase or program properly, then the EPE bit will be set to the Logic 1 state.
The EPE bit will not be set if an erase or program operation aborts for any reason, such as an attempt to erase or
program a protected region. The EPE bit is updated after every erase and program operation.
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10. Deep Power-Down
During normal operation, the device will be placed in the standby mode to consume less power as long as the CS pin
remains deasserted and no internal operation is in progress. The Deep Power-Down command offers the ability to place
the device into an even lower power consumption state called the Deep Power-Down mode.
When the device is in the Deep Power-Down mode, all commands including the Status Register Read command will be
ignored with the exception of the Resume from Deep Power-Down command. Since all commands will be ignored, the
mode can be used as an extra protection mechanism against program and erase operations.
Entering the Deep Power-Down mode is accomplished by simply asserting the CS pin, clocking in the opcode B9h, and
then deasserting the CS pin. Any additional data clocked into the device after the opcode will be ignored. When the CS
pin is deasserted, the device will enter the Deep Power-Down mode within the maximum time of tEDPD
.
The complete opcode must be clocked in before the CS pin is deasserted; otherwise, the device will abort the operation
and return to the standby mode once the CS pin is deasserted. In addition, the device will default to the standby mode
after a power cycle.
The Deep Power-Down command will be ignored if an internally self-timed operation such as a program or erase cycle is
in progress. The Deep Power-Down command must be reissued after the internally self-timed operation has been
completed in order for the device to enter the Deep Power-Down mode.
Figure 10-1. Deep Power-Down
CS
tEDPD
0
1
2
3
4
5
6
7
SCK
OPCODE
1
0
1
1
1
0
0
1
SI
MSB
HIGH-IMPEDANCE
Active Current
SO
I
CC
Standby Mode Current
Deep Power-Down Mode Current
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10.1 Resume from Deep Power-Down
In order to exit the Deep Power-Down mode and resume normal device operation, the Resume from Deep Power-Down
command must be issued. The Resume from Deep Power-Down command is the only command that the device will
recognize while in the Deep Power-Down mode.
To resume from the Deep Power-Down mode, the CS pin must first be asserted and then the opcode ABh must be
clocked into the device. Any additional data clocked into the device after the opcode will be ignored. When the CS pin is
deasserted, the device will exit the Deep Power-Down mode and return to the standby mode within the maximum time of
t
RDPD. After the device has returned to the standby mode, normal command operations such as Continuous Array Read
can be resumed.
If the complete opcode is not clocked in before the CS pin is deasserted, then the device will abort the operation and
return to the Deep Power-Down mode.
Figure 10-2. Resume from Deep Power-Down
CS
tRDPD
0
1
2
3
4
5
6
7
SCK
SI
Opcode
1
0
1
0
1
0
1
1
MSB
High-impedance
Active Current
SO
I
CC
Standby Mode Current
Deep Power-Down Mode Current
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10.2 Ultra-Deep Power-Down
The Ultra-Deep Power-Down mode allows the device to consume far less power compared to the standby and Deep
Power-Down modes by shutting down additional internal circuitry. Since almost all active circuitry is shut down in this
mode to conserve power, the contents of the Buffer cannot be maintained. Therefore, any data stored in the Buffer will be
lost once the device enters the Ultra-Deep Power-Down mode.
When the device is in the Ultra-Deep Power-Down mode, all commands including the Status Register Read and Resume
from Deep Power-Down commands will be ignored. Since all commands will be ignored, the mode can be used as an
extra protection mechanism against program and erase operations.
Entering the Ultra-Deep Power-Down mode is accomplished by simply asserting the CS pin, clocking in the opcode 79h,
and then deasserting the CS pin. Any additional data clocked into the device after the opcode will be ignored. When the
CS pin is deasserted, the device will enter the Ultra-Deep Power-Down mode within the maximum time of tEUDPD
.
The complete opcode must be clocked in before the CS pin is deasserted; otherwise, the device will abort the operation
and return to the standby mode once the CS pin is deasserted. In addition, the device will default to the standby mode
after a power cycle.
The Ultra-Deep Power-Down command will be ignored if an internally self-timed operation such as a program or erase
cycle is in progress. The Ultra-Deep Power-Down command must be reissued after the internally self-timed operation
has been completed in order for the device to enter the Ultra-Deep Power-Down mode.
Figure 10-3. Ultra-Deep Power-Down
CS
tEUDPD
0
1
2
3
4
5
6
7
SCK
SI
Opcode
0
1
1
1
1
0
0
1
MSB
High-impedance
SO
Active Current
I
CC
Standby Mode Current
Ultra-Deep Power-Down Mode Current
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10.2.1 Exit Ultra-Deep Power-Down
To exit from the Ultra-Deep Power-Down mode, the CS pin must simply be pulsed by asserting the CS pin, waiting the
minimum necessary tCSLU time, and then deasserting the CS pin again. To facilitate simple software development, a
dummy byte opcode can also be entered while the CS pin is being pulsed; the dummy byte opcode is simply ignored by
the device in this case. After the CS pin has been deasserted, the device will exit from the Ultra-Deep Power-Down mode
and return to the standby mode within a maximum time of tXUDPD. If the CS pin is reasserted before the tXUDPD time has
elapsed in an attempt to start a new operation, then that operation will be ignored and nothing will be performed. The
system must wait for the device to return to the standby mode before normal command operations such as Continuous
Array Read can be resumed.
Since the contents of the Buffer cannot be maintained while in the Ultra-Deep Power-Down mode, the Buffer will contain
undefined data when the device returns to the standby mode.
Figure 10-4. Exit Ultra-Deep Power-Down
CS
tCSLU
tXUDPD
High-impedance
SO
Active Current
ICC
Standby Mode Current
Ultra-Deep Power-Down Mode Current
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11. Buffer and Page Size Configuration
The memory array of DataFlash-L devices is actually larger than other Serial Flash devices in that extra user-accessible
bytes are provided in each page of the memory array. For the AT25PE20, there are an extra eight bytes of memory in
each page for a total of an extra 8KB (64-Kbits) of user-accessible memory.
Some applications, however, may not want to take advantage of this extra memory and instead architect their software to
operate on a binary, logical addressing scheme. To allow this, the DataFlash-L can be configured so that the Buffer and
page sizes are 256 bytes instead of the optional 264 bytes. In addition, the configuration of the Buffer and page sizes is
reversible and can be changed from 264 bytes to 256 bytes or from 256 bytes to 264 bytes. The configured setting is
stored in an internal nonvolatile register so that the Buffer and page size configuration is not affected by power cycles.
The nonvolatile register has a limit of 10,000 erase/program cycles; therefore, care should be taken to not switch
between the size options more than 10,000 times.
Devices are initially shipped from Adesto with the Buffer and page sizes set to 256 bytes. To configure the device for
default page size (256 bytes), a 4-byte opcode sequence of 3Dh, 2Ah, 80h, and A6h must be clocked into the device.
After the last bit of the opcode sequence has been clocked in, the CS pin must be deasserted to initiate the internally self-
timed configuration process and nonvolatile register program cycle. The programming of the nonvolatile register should
take place in a time of tEP, during which time, the RDY/BUSY bit in the Status Register will indicate that the device is
busy. The device does not need to be power cycled after the completion of the configuration process and register
program cycle in order for the Buffer and page size to be configured to 256 bytes.
To configure the device for optional DataFlash-L page size (264 bytes), a 4-byte opcode sequence of 3Dh, 2Ah, 80h, and
A7h must be clocked into the device. After the last bit of the opcode sequence has been clocked in, the CS pin must be
deasserted to initial the internally self-timed configuration process and nonvolatile register program cycle. The
programming of the nonvolatile register should take place in a time of tEP, during which time, the RDY/BUSY bit in the
Status Register will indicate that the device is busy. The device does not need to be power cycled after the completion of
the configuration process and register program cycle in order for the Buffer and page size to be configured to 264 bytes.
Table 11-1. Buffer and Page Size Configuration Commands
Command
Byte 1
3Dh
Byte 2
2Ah
Byte 3
80h
Byte 4
A6h
Default DataFlash-L page size (256 bytes)
Optional DataFlash-L page size (264 bytes)
3Dh
2Ah
80h
A7h
Figure 11-1. Buffer and Page Size Configuration
CS
Opcode
Byte 4
3Dh
2Ah
80h
SI
Each transition represents eight bits
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12. Manufacturer and Device ID Read
Identification information can be read from the device to enable systems to electronically query and identify the device
while it is in the system. The identification method and the command opcode comply with the JEDEC Standard for
“Manufacturer and Device ID Read Methodology for SPI Compatible Serial Interface Memory Devices”. The type of
information that can be read from the device includes the JEDEC-defined Manufacturer ID, the vendor-specific
Device ID, and the vendor-specific Extended Device Information.
The Read Manufacturer and Device ID command is limited to a maximum clock frequency of fCLK. Since not all Flash
devices are capable of operating at very high clock frequencies, applications should be designed to read the
identification information from the devices at a reasonably low clock frequency to ensure that all devices to be used in the
application can be identified properly. Once the identification process is complete, the application can then increase the
clock frequency to accommodate specific Flash devices that are capable of operating at the higher clock frequencies.
To read the identification information, the CS pin must first be asserted, and then the opcode 9Fh must be clocked into
the device. After the opcode has been clocked in, the device will begin outputting the identification data on the SO pin
during the subsequent clock cycles. The first byte to be output will be the Manufacturer ID, followed by two bytes of the
Device ID information. The fourth byte output will be the Extended Device Information (EDI) String Length, which will be
01h, indicating that one byte of EDI data follows. After the one byte of EDI data is output, the SO pin will go into a
high-impedance state; therefore, additional clock cycles will have no affect on the SO pin and no data will be output. As
indicated in the JEDEC Standard, reading the EDI String Length and any subsequent data is optional.
Deasserting the CS pin will terminate the Manufacturer and Device ID Read operation and put the SO pin into a
high-impedance state. The CS pin can be deasserted at any time and does not require that a full byte of data be read.
Table 12-1. Manufacturer and Device ID Information
Byte No.
Data Type
Value
1Fh
23h
1
2
3
4
5
Manufacturer ID
Device ID (Byte 1)
Device ID (Byte 2)
00h
Extended Device Information (EDI) String Length
[Optional to Read] EDI Byte 1
01h
00h
Table 12-2. Manufacturer and Device ID Details
Hex
Data Type
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value Details
JEDEC Assigned Code
Manufacturer ID
1Fh
23h
00h
JEDEC code: 0001 1111 (1Fh for Adesto)
0
0
0
0
0
1
0
1
0
0
1
0
1
1
1
1
1
0
Family Code
Density Code
0
Family code: 001 (AT45Dxxx Family)
Density code: 00011 (2-Mbit)
Device ID (Byte 1)
Device ID (Byte 2)
0
Sub Code
0
Product Variant
Sub code:
000 (Standard Series)
Product variant:00000
0
0
0
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Table 12-3. EDI Data
Hex
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value Details
Byte Number
RFU
0
Device Revision
RFU:
Reserved for Future Use
5
00h
Device revision:00000 (Initial Version)
0
0
0
0
0
0
0
Figure 12-1. Read Manufacturer and Device ID
CS
0
6
7
8
14 15 16
22 23 24
30 31 32
38 39 40
47
SCK
SI
Opcode
9Fh
High-impedance
1Fh
23h
00h
01h
EDI
00h
EDI
SO
Manufacturer ID
Device ID
Byte 1
Device ID
Byte 2
String Length
Data Byte 1
Note: Each transition
shown for SI and SO represents one byte (eight bits)
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13. Software Reset
In some applications, it may be necessary to prematurely terminate a program or erase cycle early rather than wait the
hundreds of microseconds or milliseconds necessary for the program or erase operation to complete normally. The
Software Reset command allows a program or erase operation in progress to be ended abruptly and returns the device
to an idle state.
To perform a Software Reset, the CS pin must be asserted and a 4-byte command sequence of F0h, 00h, 00h, and 00h
must be clocked into the device. Any additional data clocked into the device after the last byte will be ignored. When the
CS pin is deasserted, the program or erase operation currently in progress will be terminated within a time tSWRST. Since
the program or erase operation may not complete before the device is reset, the contents of the page being programmed
or erased cannot be guaranteed to be valid.
The Software Reset command has no effect on the states of the Sector Protection Register or the Buffer and page size
configuration.
The complete 4-byte opcode must be clocked into the device before the CS pin is deasserted; otherwise, no reset
operation will be performed.
Table 13-1. Software Reset
Command
Byte 1
Byte 2
Byte 3
Byte 4
Software Reset
F0h
00h
00h
00h
Figure 13-1. Software Reset
CS
F0h
00h
00h
00h
SI
Each transition represents eight bits
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14. Operation Mode Summary
The commands described previously can be grouped into four different categories to better describe which commands
can be executed at what times.
Group A commands consist of:
1. Main Memory Page Read
2. Continuous Array Read (SPI)
3. Read Sector Protection Register
4. Read Security Register
5. Buffer Read
Group B commands consist of:
1. Page Erase
2. Block Erase
3. Sector Erase
4. Chip Erase
5. Main Memory Page to the Buffer Transfer
6. Main Memory Page to the Buffer Compare
7.
8.
Buffer to Main Memory Page Program with Built-In Erase
Buffer to Main Memory Page Program without Built-In Erase
9. Main Memory Page Program through the Buffer with Built-In Erase
10. Main Memory Byte/Page Program through Buffer without Built-In Erase
11. Auto Page Rewrite
12. Read-Modify-Write
Group C commands consist of:
1. Buffer Write
2. Status Register Read
3. Manufacturer and Device ID Read
Group D commands consist of:
1. Erase Sector Protection Register
2. Program Sector Protection Register
3. Buffer and Page Size Configuration
If a Group A command is in progress (not fully completed), then another command in Group A, B, C, or D should not be
started. However, during the internally self-timed portion of Group B commands, any command in Group C can be
executed. The Group B commands using the Buffer should use Group C commands. Finally, during the internally
self-timed portion of a Group D command, only the Status Register Read command should be executed.
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15. Command Tables
Table 15-1. Read Commands
Command
Opcode
D2h
01h
Main Memory Page Read
Continuous Array Read (Low Power Mode)
Continuous Array Read (Low Frequency)
Continuous Array Read (High Frequency)
Continuous Array Read (Legacy Command – Not Recommended for New Designs)
Buffer Read (Low Frequency)
03h
0Bh
E8h
D1h
D4h
Buffer Read (High Frequency)
Table 15-2. Program and Erase Commands
Command
Opcode
Buffer Write
84h
Buffer to Main Memory Page Program with Built-In Erase
Buffer to Main Memory Page Program without Built-In Erase
Main Memory Page Program through Buffer with Built-In Erase
Main Memory Byte/Page Program through Buffer without Built-In Erase
Page Erase
83h
88h
82h
02h
81h
Block Erase
50h
Sector Erase
7Ch
C7h + 94h + 80h + 9Ah
58h
Chip Erase
Read-Modify-Write through Buffer 1
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Table 15-3. Protection and Security Commands
Command
Opcode
Enable Sector Protection
3Dh + 2Ah + 7Fh + A9h
3Dh + 2Ah + 7Fh + 9Ah
3Dh + 2Ah + 7Fh + CFh
3Dh + 2Ah + 7Fh + FCh
32h
Disable Sector Protection
Erase Sector Protection Register
Program Sector Protection Register
Read Sector Protection Register
Read Security Register
77h
Table 15-4. Additional Commands
Command
Opcode
Main Memory Page to Buffer Transfer
Main Memory Page to Buffer Compare
Auto Page Rewrite
53h
60h
58h
Deep Power-Down
B9h
Resume from Deep Power-Down
Ultra-Deep Power-Down
ABh
79h
Status Register Read
D7h
Manufacturer and Device ID Read
Configure Default 256 Byte Page Size
Configure Optional 264 Byte DataFlash-L Page Size
Software Reset
9Fh
3Dh + 2Ah + 80h + A6h
3Dh + 2Ah + 80h + A7h
F0h + 00h + 00h + 00h
Table 15-5. Legacy Commands(1)
Command
Opcode
Buffer Read
54H
52H
68H
57H
Main Memory Page Read
Continuous Array Read
Status Register Read
Note: 1. Legacy commands are not recommended for new designs.
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Table 15-6. Detailed Bit-level Addressing Sequence for Default Page Size (256 bytes)
Page Size = 256-bytes Address Byte Address Byte
Address Byte
Additional
Dummy
Bytes
Opcode
Opcode
01h
02h
03h
0Bh
1Bh
32h
50h
53h
58h (1)
58h (2)
60h
77h
79h
7Ch
81h
82h
83h
84h
88h
9Fh
B9h
ABh
D1h
D2h
D4h
D7h
E8h
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
0
0
1
0
0
0
0
1
1
1
1
0
0
0
0
0
0
1
1
0
0
0
0
1
0
0
0
0
1
1
1
1
1
1
0
1
1
1
0
0
0
0
0
1
1
0
1
1
1
1
0
0
0
0
1
1
0
0
0
1
1
0
0
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
0
1
0
1
0
0
0
0
1
1
0
0
1
1
1
1
1
0
1
0
0
0
1
0
0
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
1
1
0
0
1
0
0
0
1
1
0
1
0
1
0
0
1
1
1
1
0
0
1
0
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
A
A
X
X
A
A
A
A
X
A
A
A
A
A
X
X
A
A
A
A
X
A
A
A
A
A
X
X
A
A
A
A
X
A
A
A
A
A
X
X
X
X
A
X
X
A
A
A
A
A
X
X
X
X
A
X
X
A
A
A
A
A
X
X
X
X
A
X
X
A
A
A
A
A
X
X
X
X
A
X
X
A
A
A
A
A
A
A
X
X
X
X
A
X
X
A
A
A
A
A
X
X
X
X
A
X
X
A
A
A
A
A
X
X
X
X
A
X
X
N/A
N/A
N/A
1
X
A
A
X
A
A
X
A
A
2
X
X
X
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
4
X
A
X
X
A
X
X
A
X
X
A
A
X
A
X
X
X
X
N/A
X
N/A
X
N/A
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
A
A
A
A
X
A
A
A
A
A
X
A
A
A
A
A
X
A
X
A
A
A
X
A
X
A
A
A
X
A
X
A
A
A
X
A
X
A
A
A
X
A
X
A
A
A
X
A
X
A
A
A
X
A
X
X
A
X
A
X
X
X
A
X
A
X
X
X
A
X
A
X
X
X
A
X
A
X
X
X
A
X
A
X
X
X
A
X
A
X
X
X
A
X
A
X
X
A
X
X
A
A
X
A
X
X
X
A
X
A
X
N/A
N/A
N/A
X
N/A
N/A
N/A
X
N/A
N/A
N/A
A
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
A
X
X
A
X
X
A
X
X
A
X
X
A
X
X
A
X
X
A
X
X
A
X
X
A
X
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
X
A
A
X
X
A
1
N/A
X
N/A
A
N/A
A
N/A
4
X
X
X
X
X
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
1. Shown to indicate when Auto Page Rewrite Operation is executed.
2. Shown to indicate when Read Modify Write Operation is executed.
Note:
X = Dummy Bit
AT25PE20
DS-25PE20–139C–8/2018
37
Table 15-7. Detailed Bit-level Addressing Sequence for Optional Page Size (264 bytes)
Page Size = 264-bytes Address Byte Address Byte
Address Byte
Additional
Dummy
Bytes
Opcode
Opcode
01h
02h
03h
0Bh
1Bh
32h
50h
53h
58h(1)
58h(2)
60h
77h
79h
7Ch
81h
82h
83h
84h
88h
9Fh
B9h
ABh
D1h
D2h
D4h
D7h
E8h
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
0
0
1
0
0
0
0
1
1
1
1
0
0
0
0
0
0
1
1
0
0
0
0
1
0
0
0
0
1
1
1
1
1
1
0
1
1
1
0
0
0
0
0
1
1
0
1
1
1
1
0
0
0
0
1
1
0
0
0
1
1
0
0
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
0
1
0
1
0
0
0
0
1
1
0
0
1
1
1
1
1
0
1
0
0
0
1
0
0
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
1
1
0
0
1
0
0
0
1
1
0
1
0
1
0
0
1
1
1
1
0
0
1
0
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
P
P
X
X
P
P
P
P
X
P
P
P
P
P
X
X
P
P
P
X
X
B
B
B
B
B
X
X
X
X
B
X
X
B
B
B
B
B
X
X
X
X
B
X
X
B
B
B
B
B
X
X
X
X
B
X
X
B
B
B
B
B
X
X
X
X
B
X
X
B
B
B
B
B
X
X
X
X
B
X
X
B
B
B
B
B
B
B
X
X
X
X
B
X
X
B
B
B
B
B
X
X
X
X
B
X
X
B
B
B
B
B
X
X
X
X
B
X
X
N/A
N/A
N/A
1
X
P
B
X
P
B
X
P
B
2
X
X
X
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
4
X
X
X
X
P
X
X
P
X
X
P
B
X
P
X
X
X
X
N/A
X
N/A
X
N/A
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
P
P
P
P
X
P
P
P
P
P
X
P
P
P
P
P
X
P
X
P
P
P
X
P
X
P
P
P
X
P
X
P
P
P
X
P
X
P
P
P
X
P
X
P
P
P
X
P
X
P
P
P
X
P
X
X
B
X
B
X
X
X
B
X
B
X
X
X
B
X
B
X
X
X
B
X
B
X
X
X
B
X
B
X
X
X
B
X
B
X
X
X
B
X
B
X
X
X
B
X
B
X
X
P
X
X
P
B
X
P
X
X
X
B
X
P
X
N/A
N/A
N/A
X
N/A
N/A
N/A
X
N/A
N/A
N/A
B
X
X
X
X
X
X
X
X
X
X
X
X
X
P
X
X
P
X
X
P
X
X
P
X
X
P
X
X
P
X
X
P
X
X
P
X
X
P
X
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
B
X
P
B
X
X
B
1
N/A
X
N/A
P
N/A
B
N/A
4
X
X
X
X
P
P
P
P
P
P
P
P
P
B
B
B
B
B
B
B
B
1. Shown to indicate when Auto Page Rewrite Operation is executed.
2. Shown to indicate when Read Moodify Write Operation is executed.
Note:
P = Page Address Bit B = Byte/Buffer Address Bit X = Dummy Bit
AT25PE20
DS-25PE20–139C–8/2018
38
16. Power-On/Reset State
When power is first applied to the device, or when recovering from a reset condition, the output pin (SO) will be in a high
impedance state, and a high-to-low transition on the CSB pin will be required to start a valid instruction. The SPI mode
(Mode 3 or Mode 0) will be automatically selected on every falling edge of CSB by sampling the inactive clock state.
16.1 Power-Up/Power-Down Voltage and Timing Requirements
As the device initializes, there will be a transient current demand. The system needs to be capable of providing this
current to ensure correct initialization. During power-up, the device must not be accessed for at least the minimum tVCSL
time after the supply voltage reaches the minimum VCC level. While the device is being powered-up, the internal Power-
On Reset (POR) circuitry keeps the device in a reset mode until the supply voltage rises above the maximum POR
threshold value (VPOR). During this time, all operations are disabled and the device will not respond to any commands.
After power-up, the device will be in the standby mode.
If the first operation to the device after power-up will be a program or erase operation, then the operation cannot be
started until the supply voltage reaches the minimum VCC level and an internal device delay has elapsed. This delay will
be a maximum time of tPUW
.
Table 16-1. Voltage and Timing Requirements for Power-Up/Power-Down
Symbol
Parameter
Min
Max
Units
V
(1)
VPWD
VCC for device initialization
1.0
(1)
tPWD
Minimum duration for device initialization
Minimum VCC to chip select low time for Read command
VCC rise time
300
70
µs
tVCSL
µs
(1)
tVR
1
500000
µs/V
V
VPOR
tPUW
Power on reset voltage
1.45
1.6
3
Power up delay time before Program or Erase is allowed
ms
1. Not 100% tested (value guaranteed by design and characterization).
Figure 16-1. Power-Up Timing
VCC
VCC min
VPOR max
tPUW
Full Operation Permitted
Read Operation
Permitted
tVCSL
VPWD max
tPWD
tVR
Time
AT25PE20
DS-25PE20–139C–8/2018
39
17. System Considerations
The serial interface is controlled by the Serial Clock (SCK), Serial Input (SI), and Chip Select (CS) pins. These signals
must rise and fall monotonically and be free from noise. Excessive noise or ringing on these pins can be misinterpreted
as multiple edges and will cause improper operation of the device. PCB traces must be kept to a minimum distance or
appropriately terminated to ensure proper operation. If necessary, decoupling capacitors can be added on these pins to
provide filtering against noise glitches.
As system complexity continues to increase, voltage regulation is becoming more important. A key element of any
voltage regulation scheme is its current sourcing capability. Like all Flash memories, the peak current for DataFlash-L
devices occurs during the programming and erasing operations. The supply voltage regulator needs to be able to supply
this peak current requirement. An under specified regulator can cause current starvation. Besides increasing system
noise, current starvation during programming or erasing can lead to improper operation and possible data corruption.
AT25PE20
DS-25PE20–139C–8/2018
40
18. Electrical Specifications
18.1 Absolute Maximum Ratings*
*Notice: Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent
damage to the device. This is a stress rating only
and functional operation of the device at these or
any other conditions beyond those indicated in
the operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect device
reliability.Voltage extremes referenced in the
“Absolute Maximum Ratings” are intended to
accommodate short duration
Temperature under Bias . . . . . . . -55°C to +125°C
Storage Temperature. . . . . . . . . . -65°C to +150°C
Absolute Maximum Vcc . . . . . . . . . . . . . . . . .3.96V
All Output Voltages with Respect to Ground
undershoot/overshoot conditions and does not
imply or guarantee functional device operation at
these levels for any extended period of time.
. . . . . . . . -0.6V to 4.2V (Max VCC of 3.6V + 0.6V)
All Input Voltages with Respect to Ground
(excluding VCC pin, including NC pins)
. . . . . . . . -0.6V to 4.2V (Max VCC of 3.6V + 0.6V)
18.2 DC and AC Operating Range
AT25PE20
-40°C to 85°C
1.65V to 3.6V
Operating Temperature (Case)
VCC Power Supply
Industrial
AT25PE20
DS-25PE20–139C–8/2018
41
18.3 DC Characteristics
1.65V to 3.6V
Typ
2.3V to 3.6V
Typ
Symbol Parameter
Condition(3)
Min
Max
Min
Max
Units
Ultra-Deep Power-
IUDPD
CS= VCC. All other inputs at
0V or VCC
0.5
6
2
0.4
8
2
µA
Down Current
Deep Power-Down
Current
CS= VCC. All other inputs at
0V or VCC
IDPD
12
40
12
40
µA
µA
CS= VCC. All other inputs at
0V or VCC
ISB
Standby Current
25
25
f = 1MHz; IOUT = 0mA
(1)(2)
(1)(2)
ActiveCurrent, Low
Power Read (01h)
Operation
6
9
6
9
mA
ICC1
f = 15MHz; IOUT = 0mA
f = 50MHz; IOUT = 0mA
7
10
12
7
10
12
mA
mA
10
10
Active Current,
Read Operation
ICC2
f = 85MHz; IOUT = 0mA
CS = VCC
12
15
12
12
15
12
mA
mA
Active Current,
Program Operation
(1)(2)
(1)(2)
ICC3
10
8
10
8
Active Current,
Erase Operation
ICC4
ILI
CS = VCC
12
1
12
1
mA
µA
µA
Input Load Current
All inputs at CMOS levels
All inputs at CMOS levels
Output Leakage
Current
ILO
1
1
VCC
0.2
x
VCC
0.3
x
VIL
Input Low Voltage
Input High Voltage
V
VCC
0.8
x
VCC
0.7
x
-
VIH
V
V
V
VOL
VOH
Output Low Voltage IOL = 100µA
0.2
0.4
Output High
IOH = -100µA
Voltage
VCC
0.2V
-
VCC
0.2V
Notes: 1. Typical values measured at 1.8V @ 25°C for the 1.65V to 3.6V range.
2. Typical values measured at 3.0V @ 25°C for the 2.3V to 3.6V range.
3. All inputs (SI, SCK, CS, WP, and RESET) are guaranteed by design to be 5V tolerant.
18.4 AC Characteristics
1.65V to 3.6V
Typ
2.3V to 3.6V
Symbol
fSCK
Parameter
Min
Max
70
Min
Typ
Max
70
Units
MHz
MHz
SCK Frequency
fCAR1
SCK Frequency for Continuous Read
70
85
33
SCK Frequency for Continuous Read
(Low Frequency)
fCAR2
33
MHz
AT25PE20
DS-25PE20–139C–8/2018
42
1.65V to 3.6V
Typ
2.3V to 3.6V
Typ
Symbol
Parameter
Min
Max
Min
Max
Units
SCK Frequency for Continuous Read
(Low Power Mode – 01h Opcode)
fCAR3
15
15
MHz
tWH
tWL
SCK High Time
4
4
4
4
ns
ns
SCK Low Time
(1)
tSCKR
SCK Rise Time, Peak-to-peak
SCK Fall Time, Peak-to-peak
Minimum CS High Time
CS Setup Time
0.1
0.1
20
6
0.1
0.1
20
5
V/ns
V/ns
ns
(1)
tSCKF
tCS
tCSS
tCSH
tSU
tH
ns
CS Hold Time
5
5
ns
Data In Setup Time
2
2
ns
Data In Hold Time
1
1
ns
tHO
Output Hold Time
0
0
ns
(1)
tDIS
Output Disable Time
Output Valid
8
7
1
1
3
6
6
1
1
3
ns
tV
ns
tWPE
tWPD
WP Low to Protection Enabled
WP High to Protection Disabled
CS High to Ultra-Deep Power-Down
µs
µs
(1)
tEUDPD
µs
Minimum CS Low Time to Exit Ultra-Deep
Power-Down
tCSLU
20
20
ns
tXUDPD
Exit Ultra-Deep Power-Down Time
CS High to Deep Power-Down
Resume from Deep Power-Down Time
Page to Buffer Transfer Time
Page to Buffer Compare Time
RESET Pulse Width
240
2
120
2
µs
µs
µs
µs
µs
µs
µs
µs
(1)
tEDPD
tRDPD
35
35
tXFR
tCOMP
tRST
100
100
100
100
10
10
tREC
RESET Recovery Time
1
1
tSWRST
Software Reset Time
35
35
Note: 1. Values are based on device characterization, not 100% tested in production.
AT25PE20
DS-25PE20–139C–8/2018
43
18.5 Program and Erase Characteristics
Symbol
Parameter
Typ
Max
35
3
Typ
Max
25
3
Units
Page Erase and Programming Time (256/264
bytes)
tEP
10
10
ms
tP
Page Programming Time
Byte Programming Time
Page Erase Time
1.5
8
1.5
8
ms
µs
ms
ms
ms
s
tBP
tPE
tBE
tSE
tCE
6
25
35
550
4
6
25
35
550
4
Block Erase Time
25
350
3
25
350
3
Sector Erase Time
Chip Erase Time
19. Input Test Waveforms and Measurement Levels
0.9VCC
AC
AC
Driving
Levels
VCC/2
Measurement
Level
0.1VCC
t , t < 2ns (10% to 90%)
R
F
20. Output Test Load
Device
Under
Test
30pF
AT25PE20
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44
21. Utilizing the RapidS Function
To take advantage of the RapidS function’s ability to operate at higher clock frequencies, a full clock cycle must be used
to transmit data back and forth across the serial bus. The DataFlash-L is designed to always clock its data out on the
falling edge of the SCK signal and clock data in on the rising edge of SCK.
For full clock cycle operation to be achieved, when the DataFlash-L is clocking data out on the falling edge of SCK, the
host controller should wait until the next falling edge of SCK to latch the data in. Similarly, the host controller should clock
its data out on the rising edge of SCK in order to give the DataFlash-L a full clock cycle to latch the incoming data in on
the next rising edge of SCK.
Figure 21-1. RapidS Mode
Slave CS
1
8
1
8
1
2
3
4
5
6
7
2
3
4
5
6
7
SCK
MOSI
MISO
B
E
A
C
D
MSB
LSB
BYTE-MOSI
H
G
I
F
MSB
LSB
BYTE-SO
MOSI = Master Out, Slave In
MISO = Master In, Slave Out
The Master is the host controller and the Slave is the DataFlash.
The Master always clocks data out on the rising edge of SCK and always clocks data in on the falling edge of SCK.
The Slave always clocks data out on the falling edge of SCK and always clocks data in on the rising edge of SCK.
A. Master clocks out first bit of BYTE-MOSI on the rising edge of SCK
B. Slave clocks in first bit of BYTE-MOSI on the next rising edge of SCK
C. Master clocks out second bit of BYTE-MOSI on the same rising edge of SCK
D. Last bit of BYTE-MOSI is clocked out from the Master
E. Last bit of BYTE-MOSI is clocked into the slave
F. Slave clocks out first bit of BYTE-SO
G. Master clocks in first bit of BYTE-SO
H. Slave clocks out second bit of BYTE-SO
I. Master clocks in last bit of BYTE-SO
AT25PE20
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Figure 21-2. Command Sequence for Read/Write Operations for Page Size 256 bytes
(Except Status Register Read, Manufacturer and Device ID Read)
SI (Input)
CMD
8-bits
8-bits
8-bits
X X X X X X X X X X X X X X X X X X X X X X X X
LSB
MSB
6 Dummy
Bits
Page Address
(A17 - A8)
Byte/Buffer Address
(A7 - A0/BFA7 - BFA0)
Figure 21-3. Command Sequence for Read/Write Operations for Page Size 264 bytes
(Except Status Register Read, Manufacturer and Device ID Read)
SI (Input)
MSB
CMD
8-bits
8-bits
8-bits
X
X X X X X X X X X X X X X X X
X X X X X X X X
LSB
5 Dummy
Bits
Page Address
(PA9 - PA0)
Byte/Buffer Address
(BA8 - BA0/BFA8 - BFA0)
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22. AC Waveforms
Four different timing waveforms are shown in Figure 22-1 through F1ig.6u5reV2to2-34..6WV aveform 12.s3hVotwos3t.h6eVSCK signal being
low when CS makes a high-to-low transition, and Waveform 2 shows the SCK signal being high when CS makes a
high-to-low transition. In both cases, output SO becomes valid while the SCK signal is still low (SCK low time is specified
as tWL). Timing Waveforms 1 and 2 conform to RapidS serial interface but for frequencies only up to 70MHz.
Waveforms 1 and 2 are compatible with SPI Mode 0 and SPI Mode 3, respectively.
Waveform 3 and 4 illustrate general timing diagrams for RapidS serial interface. These are similar to Waveform 1 and 2,
except that output SO is not restricted to become valid during the tWL period. These timing waveforms are valid over the
full frequency range (maximum frequency = 70MHz) of the RapidS serial case.
Figure 22-1. Waveform 1 = SPI Mode 0 Compatible
tCS
CS
tCSS
tWH
tWL
tCSH
SCK
SO
SI
tV
tHO
tDIS
High-impedance
tSU
High-impedance
Valid Out
tH
Valid In
Figure 22-2. Waveform 2 = SPI Mode 3 Compatible
tCS
CS
tCSS
tWL
tWH
tCSH
SCK
SO
tV
tHO
tDIS
High Z
High-impedance
Valid Out
tH
tSU
Valid In
SI
AT25PE20
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47
Figure 22-3. Waveform 3 = RapidS Mode 0
tCS
CS
tCSS
tWH
tWL
tCSH
SCK
SO
SI
tV
tHO
tDIS
High-impedance
tSU
High-impedance
Valid Out
tH
Valid In
Figure 22-4. Waveform 4 = RapidS Mode 3
tCS
CS
tCSS
tWL
tWH
tCSH
SCK
SO
tV
tHO
tDIS
High Z
High-impedance
Valid Out
tH
tSU
Valid In
SI
AT25PE20
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23. Write Operations
The following block diagram and waveforms illustrate the various write sequences available.
Figure 23-1. Block Diagram
Flash Memory Array
Page (256/264 bytes)
Buffer To
Main Memory
Page Program
Buffer (256/264 bytes)
Buffer
Write
I/O Interface
SI
Figure 23-2. Buffer Write
Completes Writing into Selected Buffer
CS
Default Page Size
16 Dummy Bits + BFA7-BFA0
CMD
X
X···X, BFA8
BFA7-0
n
n + 1
Last Byte
SI (Input)
Figure 23-3. Buffer to Main Memory Page Program
Starts Self-timed Erase/Program Operation
CS
Binary Page Size
A17-A8 + 8 Dummy Bits
CMD
PA9-7
PA6-0, X
XXXX XXX
SI (Input)
n
= 1st byte read
n+1 = 2nd byte read
Each transition represents eight bits
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49
24. Read Operations
The following block diagram and waveforms illustrate the various read sequences available.
Figure 24-1. Block Diagram
Flash Memory Array
Page (256/264 bytes)
Main Memory
Page To
Buffer
Buffer (256/264 bytes)
Buffer
Read
Main Memory
Page Read
I/O Interface
SO
Figure 24-2. Main Memory Page Read
CS
Address for Default Page Size
A16
A15-A8
A7-A0
CMD
PA8-7
PA6-0, BA8
BA7-0
X
X
SI (Input)
4 Dummy Bytes
SO (Output)
n
n + 1
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Figure 24-3. Main Memory Page to Buffer Transfer
Data From the selected Flash Page is read into the Buffer
Starts Reading Page Data into Buffer
CS
Default Page Size
A17-A8 + 8 Dummy Bits
...
X, PA9-7
X
CMD
PA6-0, X
XXXX XXXX
SI (Input)
SO (Output)
Figure 24-4. Buffer Read
CS
Address for Default Page Size
16 Dummy Bits + BFA7-BFA0
...
CMD
X
X
X, BFA8
BFA7-0
X
SI (Input)
No Dummy Byte (opcode D1h)
1 Dummy Byte (opcode D4h)
SO (Output)
n
n + 1
Each transition represents eight bits
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25. Detailed Bit-level Read Waveforms: RapidS Mode 0/Mode 3
Figure 25-1. Continuous Array Read (Legacy Opcode E8h)
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34
62 63 64 65 66 67 68 69 70 71 72
SCK
SI
Opcode
Address Bits
32 Dummy Bits
1
1
1
0
1
0
0
0
A
A
A
A
A
A
A
A
A
X
X
X
X
X
X
MSB
MSB
MSB
Data Byte 1
High-impedance
D
D
D
D
D
D
D
D
D
D
SO
MSB
MSB
Figure 25-2. Continuous Array Read (Opcode 0Bh)
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
SCK
SI
Opcode
Address Bits A17 - A0
Dummy Bits
X
0
0
0
0
1
0
1
1
A
A
A
A
A
A
A
A
A
X
X
X
X
X
X
X
MSB
MSB
MSB
Data Byte 1
High-impedance
D
D
D
D
D
D
D
D
D
D
SO
MSB
MSB
Figure 25-3. Continuous Array Read (Opcode 01h or 03h)
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39 40
SCK
SI
Opcode
Address Bits A17-A0
0
0
0
0
0
0
1
1
A
A
A
A
A
A
A
A
A
MSB
MSB
Data Byte 1
High-impedance
D
D
D
D
D
D
D
D
D
D
SO
MSB
MSB
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52
Figure 25-4. Main Memory Page Read (Opcode D2h)
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34
62 63 64 65 66 67 68 69 70 71 72
SCK
SI
Opcode
Address Bits
32 Dummy Bits
1
1
0
1
0
0
1
0
A
A
A
A
A
A
A
A
A
X
X
X
X
X
X
MSB
MSB
MSB
Data Byte 1
High-impedance
D
D
D
D
D
D
D
D
D
D
SO
MSB
MSB
Figure 25-5. Buffer Read (Opcode D4h)
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
SCK
Address Bits
Default Page Size = 16 Dummy Bits + BFA7-BFA0
Optional DataFlash-Lite Page Size =
15 Dummy Bits + BFA8-BFA0
Dummy Bits
Opcode
1
1
0
1
0
1
0
0
X
X
X
X
X
X
A
A
A
X
X
X
X
X
X
X
X
SI
MSB
MSB
MSB
Data Byte 1
High-impedance
D
D
D
D
D
D
D
D
D
D
SO
MSB
MSB
Figure 25-6. Buffer Read – Low Frequency (Opcode D1h)
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39 40
SCK
Address Bits
Default Page Size = 16 Dummy Bits + BFA7-BFA0
Optional DataFlash Page Size =
15 Dummy Bits + BA8-BFA0
Opcode
1
1
0
1
0
0
0
1
X
X
X
X
X
X
A
A
A
SI
MSB
MSB
Data Byte 1
High-impedance
D
D
D
D
D
D
D
D
D
D
SO
MSB
MSB
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53
Figure 25-7. Read Sector Protection Register (Opcode 32h)
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39 40
SCK
SI
Opcode
Dummy Bits
0
0
1
1
0
0
1
0
X
X
X
X
X
X
X
X
X
MSB
MSB
Data Byte 1
High-impedance
D
D
D
D
D
D
D
D
D
SO
MSB
MSB
Figure 25-8. Read Security Register (Opcode 77h)
CS
0
1
2
3
4
5
6
7
8
9
10 11 12
29 30 31 32 33 34 35 36 37 38 39 40
SCK
SI
Opcode
Dummy Bits
0
1
1
1
0
1
1
1
X
X
X
X
X
X
X
X
X
MSB
MSB
Data Byte 1
High-impedance
D
D
D
D
D
D
D
D
D
SO
MSB
MSB
Figure 25-9. Status Register Read (Opcode D7h)
CS
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
SCK
SI
Opcode
1
1
0
1
0
1
1
1
MSB
Status Register Data
Status Register Data
High-impedance
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
SO
MSB
MSB
MSB
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Figure 25-10. Manufacturer and Device Read (Opcode 9Fh)
CS
0
6
7
8
14 15 16
22 23 24
30 31 32
38 39 40
47
SCK
SI
Opcode
9Fh
High-impedance
1Fh
23h
00h
01h
EDI
00h
EDI
SO
Manufacturer ID
Device ID
Byte 1
Device ID
Byte 2
String Length
Data Byte 1
Note: Each transition
shown for SI and SO represents one byte (eight bits)
Figure 25-11.Reset Timing
CS
t
t
CSS
REC
SCK
RESET
t
RST
High-impedance
High-impedance
SO (Output)
SI (Input)
Note: 1. The CS signal should be in the high state before the RESET signal is deasserted.
AT25PE20
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55
26. Auto Page Rewrite Flowchart
Figure 26-1. Algorithm for Programming or Re-programming of the Entire Array Sequentially
START
Provide Address
and Data
Buffer Write
(84h)
Main Memory Page Program
through Buffer
(82h)
Buffer To Main
Memory Page Program
(83h)
END
Notes: 1. This type of algorithm is used for applications in which the entire array is programmed sequentially, filling the
array page-by-page.
2. A page can be written using either a Main Memory Page Program operation or a buffer write operation
followed by a buffer to Main Memory Page Program operation.
3. The algorithm above shows the programming of a single page. The algorithm will be repeated sequentially
for each page within the entire array.
AT25PE20
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56
Figure 26-2. Algorithm for Programming or Re-programming of the Entire Array Randomly
START
Provide Address of
Page to Modify
Main Memory Page
to Buffer Transfer
(53h)
If planning to modify multiple
bytes currently stored within
a page of the Flash array
Buffer Write
(84h)
Main Memory Page Program
through Buffer
(82h)
Buffer to Main
Memory Page Program
(83h)
(2)
Auto Page Rewrite
(58h)
Increment Page
(2)
Address Pointer
END
Notes: 1. To preserve data integrity, each page of an DataFlash-L sector must be updated/rewritten at least once
within every 50,000 cumulative page erase and program operations.
2. A page address pointer must be maintained to indicate which page is to be rewritten. The auto page rewrite
command must use the address specified by the page address pointer
3. Other algorithms can be used to rewrite portions of the Flash array. Low-power applications may choose to
wait until 50,000 cumulative page erase and program operations have accumulated before rewriting all
pages of the sector.
AT25PE20
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57
27. Ordering Information
27.1 Ordering Detail
A T 2 5 P E 2 0 - S S H N - B
Designator
Shipping Carrier Option
B
T
Y
= Bulk (tubes)
= Tape and reel
= Trays
Product Family
25PE = DataFlash-L
Operating Voltage
N
= 1.65V minimum (1.65V to 3.6V)
Device Density
20 = 2-Mbit
Device Grade
H
= Green, NiPdAu lead finish,
Industrial temperature range
(–40°C to +85°C)
Package Option
SS = 8-lead, 0.150” narrow SOIC
S
= 8-lead, 0.208” wide SOIC
M
= 8-pad, 5 x 6 x 0.6mm UDFN
27.2 Ordering Codes (Default 256 Byte DataFlash-L Page Size)
Ordering Code
Package
Lead Finish
Operating Voltage
fSCK
Device Grade
AT25PE20-SSHN-B (1)
AT25PE20-SSHN-T(1)
AT25PE20-SHN-B(1)
AT25PE20-SHN-T(1)
AT25PE20-MHN-Y(1)
AT25PE20-MHN-T(1)
8S1
Industrial
NiPdAu
1.65V to 3.6V
70MHz
8S2
(-40°C to 85°C)
8MA1
Notes: 1. The shipping carrier suffix is not marked on the device.
Package Type
8S1
8-lead 0.150" wide, Plastic Gull Wing Small Outline (JEDEC SOIC)
8-lead 0.208" wide, Plastic Gull Wing Small Outline (EIAJ SOIC)
8S2
8MA1
8-pad (5 x 6 x 0.6mm body), Thermally Enhanced Plastic Ultra Thin Dual Flat No-lead (UDFN)
AT25PE20
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58
28. Packaging Information
28.1 8S1 – 8-lead JEDEC SOIC
C
1
E
E1
L
N
Ø
TOP VIEW
END VIEW
e
b
COMMON DIMENSIONS
(Unit of Measure = mm)
A
MIN
1.35
0.10
MAX
1.75
0.25
NOM
NOTE
SYMBOL
A1
A
–
–
A1
b
0.31
0.17
4.80
3.81
5.79
–
0.51
0.25
5.05
3.99
6.20
C
D
E1
E
e
–
–
D
–
–
SIDE VIEW
1.27 BSC
L
0.40
0°
–
–
1.27
8°
Notes: This drawing is for general information only.
Refer to JEDEC Drawing MS-012, Variation AA
for proper dimensions, tolerances, datums, etc.
Ø
6/22/11
DRAWING NO. REV.
TITLE
GPC
8S1, 8-lead (0.150” Wide Body), Plastic Gull Wing
Small Outline (JEDEC SOIC)
SWB
8S1
G
Package Drawing Contact:
contact@adestotech.com
AT25PE20
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59
28.2 8S2 – 8-lead EIAJ SOIC
C
1
E
E1
L
N
q
TOP VIEW
END VIEW
e
b
COMMON DIMENSIONS
(Unit of Measure = mm)
A
MIN
1.70
0.05
0.35
0.15
5.13
5.18
7.70
0.51
0°
MAX
2.16
0.25
0.48
0.35
5.35
5.40
NOM
NOTE
SYMBOL
A1
A
A1
b
4
4
C
D
E1
E
D
2
8.10
L
0.85
8°
SIDE VIEW
q
e
1.27 BSC
3
Notes: 1. This drawing is for general information only; refer to EIAJ Drawing EDR-7320 for additional information.
2. Mismatch of the upper and lower dies and resin burrs aren't included.
3. Determines the true geometric position.
4. Values b,C apply to plated terminal. The standard thickness of the plating layer shall measure between 0.007 to .021 mm.
4/15/08
REV.
GPC
DRAWING NO.
TITLE
8S2, 8-lead, 0.208” Body, Plastic Small
Outline Package (EIAJ)
Package Drawing Contact:
contact@adestotech.com
STN
8S2
F
AT25PE20
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60
28.3 8MA1 – 8-pad UDFN
E
C
Pin 1 ID
SIDE VIEW
D
y
TOP VIEW
A1
A
K
E2
Option A
0.45
Pin #1
Chamfer
(C 0.35)
8
1
2
3
Pin #1 Notch
(0.20 R)
COMMON DIMENSIONS
(Unit of Measure = mm)
(Option B)
MIN
MAX
NOM
NOTE
SYMBOL
7
A
0.45
0.55
0.60
e
D2
A1
b
0.00
0.35
0.02
0.40
0.152 REF
5.00
4.00
6.00
3.40
1.27
0.60
–
0.05
0.48
6
C
D
D2
E
4.90
3.80
5.90
3.20
5.10
4.20
6.10
3.60
5
4
b
BOTTOM VIEW
L
E2
e
L
0.50
0.00
0.20
0.75
0.08
–
y
K
–
4/15/08
GPC
YFG
DRAWING NO.
TITLE
REV.
Package Drawing Contact: 8MA1, 8-pad (5 x 6 x 0.6 mm Body), Thermally
Enhanced Plastic Ultra Thin Dual Flat No Lead
Package (UDFN)
8MA1
D
contact@adestotech.com
AT25PE20
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61
29. Revision History
Doc. Rev.
Date
Comments
DS-25PE20-139A
DS-25PE20-139B
07/2017
03/2018
Initial document release.
Change document status from ADVANCED to PRELIMINARY.
Change document status from PRELIMINARY to production.
Updated Figure 7-1.
DS-25PE20-139C
08/2018
Updated Figure 16-1.
AT25PE20
DS-25PE20–139C–8/2018
62
Corporate Office
California | USA
Adesto Headquarters
3600 Peterson Way
Santa Clara, CA 95054
Phone: (+1) 408.400.0578
Email: contact@adestotech.com
© 2017 Adesto Technologies. All rights reserved. / Rev.: DS-25PE20–139C–8/2018
Adesto®, the Adesto logo, CBRAM®, and DataFlash® are registered trademarks or trademarks of Adesto Technologies. All other marks are the property of their respective
owners. Adesto products in this datasheet are covered by certain Adesto patents registered in the United States and potentially other countries. Please refer to
http://www.adestotech.com/patents for details.
Disclaimer: Adesto Technologies Corporation makes no warranty for the use of its products, other than those expressly contained in the Company's standard warranty which is detailed in Adesto's Terms
and Conditions located on the Company's web site. The Company assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications
detailed herein at any time without notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of Adesto are granted by the
Company in connection with the sale of Adesto products, expressly or by implication. Adesto's products are not authorized for use as critical components in life support devices or systems.
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