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IS42S16400L-6T [ISSI]

Synchronous DRAM, 4MX16, 5.5ns, CMOS, PDSO54, 0.400 INCH, TSOP2-54;
IS42S16400L-6T
型号： IS42S16400L-6T
厂家： INTEGRATED SILICON SOLUTION, INC    INTEGRATED SILICON SOLUTION, INC
描述：

Synchronous DRAM, 4MX16, 5.5ns, CMOS, PDSO54, 0.400 INCH, TSOP2-54

动态存储器 光电二极管 内存集成电路
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®
IS42S16400L  
1 Meg Bits x 16 Bits x 4 Banks (64-MBIT)  
SYNCHRONOUS DYNAMIC RAM  
ISSI  
PRELIMINARY  
DECEMBER 2001  
FEATURES  
OVERVIEW  
ISSI's 64Mb Synchronous DRAM IS42S16400L is  
organized as 1,048,576 bits x 16-bit x 4-bank for improved  
performance.ThesynchronousDRAMsachievehigh-speed  
data transfer using pipeline architecture. All inputs and  
outputs signals refer to the rising edge of the clock input.  
• Clock frequency: 166, 133, 100 MHz  
• Fully synchronous; all signals referenced to a  
positive clock edge  
• Internal bank for hiding row access/precharge  
• Single 3.3V power supply  
• LVTTLinterface  
PIN CONFIGURATIONS  
54-Pin TSOP (Type II)  
• Programmable burst length  
– (1, 2, 4, 8, full page)  
VCC  
I/O0  
VCCQ  
I/O1  
I/O2  
GNDQ  
I/O3  
I/O4  
VCCQ  
I/O5  
I/O6  
GNDQ  
I/O7  
VCC  
LDQM  
WE  
1
54  
53  
52  
51  
50  
49  
48  
47  
46  
45  
44  
43  
42  
41  
40  
39  
38  
37  
36  
35  
34  
33  
32  
31  
30  
29  
28  
GND  
I/O15  
GNDQ  
I/O14  
I/O13  
VCCQ  
I/O12  
I/O11  
GNDQ  
I/O10  
I/O9  
VCCQ  
I/O8  
GND  
NC  
• Programmableburstsequence:  
Sequential/Interleave  
2
3
4
• Self refresh modes  
5
6
• 4096 refresh cycles every 64 ms  
• Random column address every clock cycle  
• Programmable CAS latency (2, 3 clocks)  
7
8
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
• Burst read/write and burst read/single write  
operationscapability  
• Burst termination by burst stop and precharge  
command  
UDQM  
CLK  
CKE  
NC  
CAS  
RAS  
CS  
• Byte controlled by LDQM and UDQM  
• Industrialtemperatureavailability  
• Package: 400-mil 54-pin TSOP II  
BA0  
BA1  
A10  
A11  
A9  
A8  
A0  
A7  
A1  
A6  
A2  
A5  
A3  
A4  
VCC  
GND  
PIN DESCRIPTIONS  
A0-A11  
BA0, BA1  
I/O0 to I/O15  
CLK  
Address Input  
WE  
Write Enable  
Bank Select Address  
Data I/O  
LDQM  
UDQM  
Vcc  
Lower Bye, Input/Output Mask  
Upper Bye, Input/Output Mask  
Power  
System Clock Input  
Clock Enable  
CKE  
GND  
VccQ  
GNDQ  
NC  
Ground  
CS  
Chip Select  
Power Supply for I/O Pin  
Ground for I/O Pin  
No Connection  
RAS  
Row Address Strobe Command  
Column Address Strobe Command  
CAS  
This document contains PRELIMINARY SPECIFICATION data. ISSI reserves the right to make changes to its products at any time without notice in order to improve design and supply the best  
possible product. We assume no responsibility for any errors which may appear in this publication. © Copyright 2001, Integrated Silicon Solution, Inc.  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
1
12/01/01  
®
IS42S16400L  
ISSI  
GENERALDESCRIPTION  
The 64Mb SDRAM is a high speed CMOS, dynamic  
random-access memory designed to operate in 3.3V  
memory systems containing 67,108,864 bits. Internally  
configured as a quad-bank DRAM with a synchronous  
interface. Each16,777,216-bitbankisorganizedas4,096  
rows by 256 columns by 16 bits.  
function enabled. Precharge one bank while accessing one  
of the other three banks will hide the precharge cycles and  
provide seamless, high-speed, random-access operation.  
SDRAM read and write accesses are burst oriented starting  
at a selected location and continuing for a programmed  
number of locations in a programmed sequence. The  
registration of an ACTIVE command begins accesses,  
followed by a READ or WRITE command. The ACTIVE  
command in conjunction with address bits registered are  
used to select the bank and row to be accessed (BA0, BA1  
select the bank; A0-A11 select the row). The READ or  
WRITE commands in conjunction with address bits reg-  
istered are used to select the starting column location for  
the burst access.  
The 64Mb SDRAM includes an AUTO REFRESH MODE,  
and a power-saving, power-down mode. All signals are  
registered on the positive edge of the clock signal, CLK.  
All inputs and outputs are LVTTL compatible.  
The 64Mb SDRAM has the ability to synchronously burst  
data at a high data rate with automatic column-address  
generation,theabilitytointerleavebetweeninternalbanks  
to hide precharge time and the capability to randomly  
change column addresses on each clock cycle during  
burst access.  
Programmable READ or WRITE burst lengths consist of  
1, 2, 4 and 8 locations or full page, with a burst terminate  
option.  
A self-timed row precharge initiated at the end of the burst  
sequence is available with the AUTO PRECHARGE  
FUNCTIONAL BLOCK DIAGRAM  
CLK  
CKE  
CS  
RAS  
CAS  
WE  
DQM  
DATA IN  
BUFFER  
COMMAND  
DECODER  
&
CLOCK  
GENERATOR  
16  
16  
REFRESH  
CONTROLLER  
MODE  
REGISTER  
I/O 0-15  
A11  
11  
Vcc/Vcc  
Q
SELF  
DATA OUT  
BUFFER  
REFRESH  
GND/GNDQ  
A10  
CONTROLLER  
16  
16  
A9  
A8  
A7  
A6  
REFRESH  
COUNTER  
A5  
A4  
4096  
A3  
A2  
A1  
A0  
BA0  
BA1  
4096  
MEMORY CELL  
ARRAY  
4096  
4096  
11  
BANK 0  
ROW  
ADDRESS  
LATCH  
ROW  
ADDRESS  
BUFFER  
11  
11  
SENSE AMP I/O GATE  
256K  
(x 16)  
COLUMN  
ADDRESS LATCH  
BANK CONTROL LOGIC  
8
BURST COUNTER  
COLUMN DECODER  
COLUMN  
ADDRESS BUFFER  
8
2
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
PIN FUNCTIONS  
Symbol  
Pin No.  
Type  
Function (In Detail)  
A0-A11  
23 to 26  
29 to 34  
22, 35  
Input Pin  
Address Inputs: A0-A11 are sampled during the ACTIVE  
command (row-address A0-A11) and READ/WRITE command (A0-A7  
with A10 defining auto precharge) to select one location out of the memory array  
in the respective bank. A10 is sampled during a PRECHARGE command to  
determine if all banks are to be precharged (A10 HIGH) or bank selected by  
BA0, BA1 (LOW). The address inputs also provide the op-code during a LOAD  
MODE REGISTER command.  
BA0, BA1  
CAS  
20, 21  
17  
Input Pin  
Input Pin  
Input Pin  
Bank Select Address: BA0 and BA1 defines which bank the ACTIVE, READ,  
WRITE or PRECHARGE command is being applied.  
CAS, in conjunction with the RAS and WE, forms the device command. See the  
"Command Truth Table" for details on device commands.  
CKE  
37  
The CKE input determines whether the CLK input is enabled. The next rising edge  
of the CLK signal will be valid when is CKE HIGH and invalid when LOW. When  
CKE is LOW, the device will be in either power-down mode, clock suspend mode,  
or self refresh mode. CKE is an asynchronous input.  
CLK  
38  
19  
Input Pin  
Input Pin  
CLK is the master clock input for this device. Except for CKE, all inputs to this  
device are acquired in synchronization with the rising edge of this pin.  
CS  
The CS input determines whether command input is enabled within the device.  
Command input is enabled when CS is LOW, and disabled with CS is HIGH. The  
device remains in the previous state when CS is HIGH.  
I/O0 to  
I/O15  
2, 4, 5, 7, 8, 10,  
11,13, 42, 44, 45,  
47, 48, 50, 51, 53  
I/O Pin  
I/O0 to I/O15 are I/O pins. I/O through these pins can be controlled in byte units  
using the LDQM and UDQM pins.  
LDQM,  
UDQM  
15, 39  
Input Pin  
LDQM and UDQM control the lower and upper bytes of the I/O buffers. In read  
mode, LDQM and UDQM control the output buffer. When LDQM or UDQM is  
LOW, the corresponding buffer byte is enabled, and when HIGH, disabled. The  
outputs go to the HIGH impedance state when LDQM/UDQM is HIGH. This  
function corresponds to OE in conventional DRAMs. In write mode, LDQM and  
UDQM control the input buffer. When LDQM or UDQM is LOW, the corresponding  
buffer byte is enabled, and data can be written to the device. When LDQM or  
UDQM is HIGH, input data is masked and cannot be written to the device.  
RAS  
WE  
18  
16  
Input Pin  
Input Pin  
RAS, in conjunction with CAS and WE, forms the device command. See the  
"Command Truth Table" item for details on device commands.  
WE, in conjunction with RAS and CAS, forms the device command. See the  
"Command Truth Table" item for details on device commands.  
VCCQ  
VCC  
3, 9, 43, 49  
1, 14, 27  
Power Supply Pin VCCQ is the output buffer power supply.  
Power Supply Pin VCC is the device internal power supply.  
Power Supply Pin GNDQ is the output buffer ground.  
Power Supply Pin GND is the device internal ground.  
GNDQ  
GND  
6, 12, 46, 52  
28, 41, 54  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
3
12/01/01  
®
IS42S16400L  
ISSI  
FUNCTION (In Detail)  
READ  
A0-A11 are address inputs sampled during the ACTIVE  
(row-address A0-A11) and READ/WRITE command (A0-A7  
with A10 defining auto PRECHARGE). A10 is sampled during  
a PRECHARGE command to determine if all banks are to  
be PRECHARGED (A10 HIGH) or bank selected by BA0,  
BA1 (LOW). The address inputs also provide the op-code  
during a LOAD MODE REGISTER command.  
The READ command selects the bank from BA0, BA1  
inputs and starts a burst read access to an active row.  
Inputs A0-A7 provides the starting column location. When  
A10 is HIGH, this command functions as an AUTO  
PRECHARGE command. When the auto precharge is  
selected, the row being accessed will be precharged at  
the end of the READ burst. The row will remain open for  
subsequent accesses when AUTO PRECHARGE is not  
selected. DQ’s read data is subject to the logic level on  
the DQM inputs two clocks earlier. When a given DQM  
signal was registered HIGH, the corresponding DQ’s will  
be High-Z two clocks later. DQ’s will provide valid data  
when the DQM signal was registered LOW.  
BankSelectAddress(BA0andBA1) defineswhichbankthe  
ACTIVE, READ, WRITE or PRECHARGE command is  
being applied.  
CAS, in conjunction with the RAS and WE, forms the  
device command. See the “Command Truth Table” for  
details on device commands.  
WRITE  
The CKE input determines whether the CLK input is  
enabled. The next rising edge of the CLK signal will be  
valid when is CKE HIGH and invalid when LOW. When  
CKE is LOW, the device will be in either power-down  
mode, CLOCK SUSPEND mode, or SELF-REFRESH  
mode. CKE is an asynchronous input.  
A burst write access to an active row is initiated with the  
WRITE command. BA0, BA1 inputs selects the bank, and  
the starting column location is provided by inputs A0-A7.  
Whether or not AUTO-PRECHARGE is used is deter-  
mined by A10.  
CLK is the master clock input for this device. Except for  
CKE, all inputs to this device are acquired in synchroni-  
zation with the rising edge of this pin.  
The row being accessed will be precharged at the end of  
the WRITE burst, if AUTO PRECHARGE is selected. If  
AUTO PRECHARGE is not selected, the row will remain  
open for subsequent accesses.  
The CS input determines whether command input is  
enabled within the device. Command input is enabled  
when CS is LOW, and disabled with CS is HIGH. The  
device remains in the previous state when CS is HIGH. I/  
O0 to I/O15 are I/O pins. I/O through these pins can be  
controlled in byte units using the LDQM and UDQM pins.  
A memory array is written with corresponding input data  
on DQ’s and DQM input logic level appearing at the same  
time. Data will be written to memory when DQM signal is  
LOW. When DQM is HIGH, the corresponding data inputs  
will be ignored, and a WRITE will not be executed to that  
byte/column location.  
LDQMandUDQMcontrolthelowerandupperbytesofthe  
I/O buffers. In read mode, LDQM and UDQM control the  
output buffer. When LDQM or UDQM is LOW, the corre-  
sponding buffer byte is enabled, and when HIGH, dis-  
abled. The outputs go to the HIGH Impedance State when  
LDQM/UDQM is HIGH. This function corresponds to OE  
in conventional DRAMs. In write mode, LDQM and UDQM  
control the input buffer. When LDQM or UDQM is LOW,  
the corresponding buffer byte is enabled, and data can be  
written to the device. When LDQM or UDQM is HIGH,  
input data is masked and cannot be written to the device.  
PRECHARGE  
The PRECHARGE command is used to deactivate the  
open row in a particular bank or the open row in all banks.  
BA0, BA1 can be used to select which bank is precharged  
or they are treated as “Don’t Care”. A10 determined  
whether one or all banks are precharged. After executing  
thiscommand,thenextcommandfortheselectedbanks(s)  
is executed after passage of the period tRP, which is the  
period required for bank precharging. Once a bank has  
been precharged, it is in the idle state and must be  
activated prior to any READ or WRITE commands being  
issued to that bank.  
RAS, in conjunction with CAS and WE , forms the device  
command. See the “Command Truth Table” item for  
details on device commands.  
AUTOPRECHARGE  
WE , in conjunction with RAS and CAS , forms the device  
command. See the “Command Truth Table” item for  
details on device commands.  
The AUTO PRECHARGE function ensures that the  
precharge is initiated at the earliest valid stage within a  
burst. This function allows for individual-bank precharge  
without requiring an explicit command. A10 to enables the  
AUTO PRECHARGE function in conjunction with a spe-  
cific READ or WRITE command. For each individual  
READ or WRITE command, auto precharge is either  
VCCQ is the output buffer power supply.  
VCC is the device internal power supply.  
GNDQ is the output buffer ground.  
GND is the device internal ground.  
4
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
enabled or disabled. AUTO PRECHARGE does not apply  
except in full-page burst mode. Upon completion of the  
READ or WRITE burst, a precharge of the bank/row that  
is addressed is automatically performed.  
BURSTTERMINATE  
The BURST TERMINATE command forcibly terminates  
the burst read and write operations by truncating either  
fixed-length or full-page bursts and the most recently  
registered READ or WRITE command prior to the BURST  
TERMINATE.  
AUTO REFRESH COMMAND  
This command executes the AUTO REFRESH operation.  
The row address and bank to be refreshed are automatically  
generated during this operation. The stipulated period (tRC)  
is required for a single refresh operation, and no other  
commands can be executed during this period. This com-  
mand is executed at least 4096 times every 64ms. During  
an AUTO REFRESH command, address bits are “Don’t  
Care”. This command corresponds to CBR Auto-refresh.  
COMMAND INHIBIT  
COMMAND INHIBIT prevents new commands from being  
executed. Operations in progress are not affected, apart  
from whether the CLK signal is enabled  
NO OPERATION  
When CS is low, the NOP command prevents unwanted  
commands from being registered during idle or wait  
states.  
SELFREFRESH  
During the SELF REFRESH operation, the row address to  
be refreshed, the bank, and the refresh interval are  
generated automatically internally. SELF REFRESH can  
be used to retain data in the SDRAM without external  
clocking, even if the rest of the system is powered down.  
The SELF REFRESH operation is started by dropping the  
CKE pin from HIGH to LOW. During the SELF REFRESH  
operation all other inputs to the SDRAM become “Don’t  
Care”.The device must remain in self refresh mode for a  
minimum period equal to tRAS or may remain in self refresh  
mode for an indefinite period beyond that.The SELF-  
REFRESH operation continues as long as the CKE pin  
remains LOW and there is no need for external control of  
any other pins.The next command cannot be executed  
until the device internal recovery period (tRC) has elapsed.  
Once CKE goes HIGH, the NOP command must be  
issued (minimum of two clocks) to provide time for the  
completion of any internal refresh in progress. After the  
self-refresh, since it is impossible to determine the ad-  
dress of the last row to be refreshed, an AUTO-REFRESH  
should immediately be performed for all addresses.  
LOAD MODE REGISTER  
During the LOAD MODE REGSITER command the mode  
register is loaded from A0-A11. This command can only  
be issued when all banks are idle.  
ACTIVE COMMAND  
When the ACTIVE COMMAND is activated, BA0, BA1  
inputs selects a bank to be accessed, and the address  
inputs on A0-A11 selects the row. Until a PRECHARGE  
command is issued to the bank, the row remains open for  
accesses.  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
5
12/01/01  
®
IS42S16400L  
ISSI  
TRUTH TABLE – COMMANDS AND DQM OPERATION(1)  
FUNCTION  
CS  
H
L
RAS CAS  
WE DQM  
ADDR  
DQs  
X
COMMAND INHIBIT (NOP)  
X
H
L
X
H
H
L
X
H
H
H
L
X
X
X
X
NO OPERATION (NOP)  
X
ACTIVE (Select bank and activate row)(3)  
READ (Select bank/column, start READ burst)(4)  
WRITE(Selectbank/column, startWRITEburst)(4)  
BURST TERMINATE  
PRECHARGE (Deactivate row in bank or banks)(5)  
AUTO REFRESH or SELF REFRESH(6,7)  
(Enter self refresh mode)  
L
X
Bank/Row  
Bank/Col  
Bank/Col  
X
X
X
L
H
H
H
L
L/H(8)  
L/H(8)  
X
L
L
Valid  
L
H
H
L
L
Active  
L
L
X
Code  
X
X
L
L
H
X
X
LOAD MODE REGISTER(2)  
Write Enable/Output Enable(8)  
Write Inhibit/Output High-Z(8)  
L
L
L
L
X
L
Op-Code  
X
—
—
—
—
—
—
—
—
—
—
Active  
High-Z  
H
NOTES:  
1. CKE is HIGH for all commands except SELF REFRESH.  
2. A0-A11 define the op-code written to the mode register.  
3. A0-A11 provide row address, and BA0, BA1 determine which bank is made active.  
4. A0-A7 (x16) provide column address; A10 HIGH enables the auto precharge feature (nonpersistent), while A10 LOW disables  
auto precharge; BA0, BA1 determine which bank is being read from or written to.  
5. A10 LOW: BA0, BA1 determine the bank being precharged. A10 HIGH: All banks precharged and BA0, BA1 are “Don’t Care.”  
6. AUTO REFRESH if CKE is HIGH, SELF REFRESH if CKE is LOW.  
7. Internal refresh counter controls row addressing; all inputs and I/Os are “Don’t Care” except for CKE.  
8. Activates or deactivates the DQs during WRITEs (zero-clock delay) and READs (two-clock delay).  
6
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
TRUTH TABLE – CKE (1-4)  
CURRENT STATE  
Power-Down  
COMMANDn  
ACTIONn  
CKEn-1  
CKEn  
X
Maintain Power-Down  
Maintain Self Refresh  
Maintain Clock Suspend  
Exit Power-Down  
Exit Self Refresh  
L
L
L
L
Self Refresh  
X
Clock Suspend  
Power-Down(5)  
Self Refresh(6)  
Clock Suspend(7)  
All Banks Idle  
All Banks Idle  
Reading or Writing  
X
L
L
COMMAND INHIBIT or NOP  
COMMAND INHIBIT or NOP  
X
L
H
H
H
L
L
Exit Clock Suspend  
Power-Down Entry  
Self Refresh Entry  
Clock Suspend Entry  
L
COMMAND INHIBIT or NOP  
AUTO REFRESH  
VALID  
H
H
H
H
L
L
SeeTRUTHTABLE–CURRENTSTATEBANKn,COMMANDTOBANKn  
H
NOTES:  
1. CKEn is the logic state of CKE at clock edge n; CKEn-1 was the state of CKE at the previous clock edge.  
2. Current state is the state of the SDRAM immediately prior to clock edge n.  
3. COMMANDn is the command registered at clock edge n, and ACTONn is a result of COMMANDn.  
4. All states and sequences not shown are illegal or reserved.  
5. Exiting power-down at clock edge n will put the device in the all banks idle state in time for clock edge n+1 (provided that tCKS is met)  
.
6. Exiting self refresh at clock edge n will put the device in all banks idle state once tXSR is met. COMMAND INHIBIT or NOP commands  
should be issued on clock edges occurring during the tXSR period. A minimum of two NOP commands must be sent during tXSR period.  
7. After exiting clock suspend at clock edge n, the device will resume operation and recognize the next command at clock edge n+1.  
TRUTH TABLE – CURRENT STATE BANK n, COMMAND TO BANK n (1-6)  
CURRENT STATE  
Any  
COMMAND (ACTION)  
CS RAS CAS WE  
COMMAND INHIBIT (NOP/Continue previous operation)  
NO OPERATION (NOP/Continue previous operation)  
ACTIVE (Select and activate row)  
H
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
X
H
L
X
H
H
L
X
H
H
H
L
Idle  
AUTO REFRESH(7)  
L
LOAD MODE REGISTER(7)  
L
L
PRECHARGE(11)  
L
H
L
L
Row Active  
READ (Select column and start READ burst)(10)  
WRITE (Select column and start WRITE burst)(10)  
PRECHARGE (Deactivate row in bank or banks)(8)  
READ (Select column and start new READ burst)(10)  
WRITE (Select column and start WRITE burst)(10)  
PRECHARGE (Truncate READ burst, start PRECHARGE)(8)  
BURST TERMINATE(9)  
H
H
L
H
L
L
H
L
L
Read  
H
H
L
H
L
(Auto  
L
Precharge  
Disabled)  
Write  
H
H
L
L
H
H
H
L
L
READ (Select column and start READ burst)(10)  
WRITE (Select column and start new WRITE burst)(10)  
PRECHARGE (Truncate WRITE burst, start PRECHARGE)(8)  
BURST TERMINATE(9)  
H
L
(Auto  
L
Precharge  
Disabled)  
H
H
L
H
L
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
7
12/01/01  
®
IS42S16400L  
ISSI  
NOTE:  
1. This table applies when CKE n-1 was HIGH and CKE n is HIGH (see Truth Table - CKE) and after tXSR has been met (if the  
previous state was SELF REFRESH).  
2. This table is bank-specific, except where noted; i.e., the current state is for a specific bank and the commands shown are those  
allowed to be issued to that bank when in that state. Exceptions are covered in the notes below.  
3. Currentstatedefinitions:  
Idle: The bank has been precharged, and tRP has been met.  
Row Active: A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and no register  
accesses are in progress.  
Read: A READ burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated.  
Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated.  
4. The following states must not be interrupted by a command issued to the same bank. COMMAND INHIBIT or NOP commands, or  
allowable commands to the other bank should be issued on any clock edge occurring during these states. Allowable commands to  
the other bank are determined by its current state and CURRENT STATE BANK n truth tables.  
Precharging: Starts with registration of a PRECHARGE command and ends when tRP is met. Once tRP is met, the bank  
will be in the idle state.  
Row Activating: Starts with registration of an ACTIVE command and ends when tRCD is met. Once tRCD is met, the bank will  
be in the row active state.  
Readw/Auto  
PrechargeEnabled: Starts with registration of a READ command with auto precharge enabled and ends when tRP has been met.  
Once tRP is met, the bank will be in the idle state.  
Writew/Auto  
PrechargeEnabled: Starts with registration of a WRITE command with auto precharge enabled and ends when tRP has been met.  
Once tRP is met, the bank will be in the idle state.  
5. The following states must not be interrupted by any executable command; COMMAND INHIBIT or NOP commands must be  
applied on each positive clock edge during these states.  
Refreshing: Starts with registration of an AUTO REFRESH command and ends when tRC is met. Once tRC is met, the  
SDRAM will be in the all banks idle state.  
Accessing Mode  
Register: Starts with registration of a LOAD MODE REGISTER command and ends when tMRD has been met. Once  
tMRD is met, the SDRAM will be in the all banks idle state.  
PrechargingAll: Starts with registration of a PRECHARGE ALL command and ends when tRP is met. Once tRP is met, all  
banks will be in the idle state.  
6. All states and sequences not shown are illegal or reserved.  
7. Not bank-specific; requires that all banks are idle.  
8. May or may not be bank-specific; if all banks are to be precharged, all must be in a valid state for precharging.  
9. Not bank-specific; BURST TERMINATE affects the most recent READ or WRITE burst, regardless of bank.  
10. READs or WRITEs listed in the Command (Action) column include READs or WRITEs with auto precharge enabled and READs  
or WRITEs with auto precharge disabled.  
11. Does not affect the state of the bank and acts as a NOP to that bank.  
8
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
(1-6)  
TRUTH TABLE – CURRENT STATE BANK n, COMMAND TO BANK m  
CURRENT STATE  
Any  
COMMAND (ACTION)  
CS RAS CAS WE  
COMMAND INHIBIT (NOP/Continue previous operation)  
NO OPERATION (NOP/Continue previous operation)  
Any Command Otherwise Allowed to Bank m  
ACTIVE (Select and activate row)  
H
L
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
X
H
X
L
X
H
X
H
L
X
H
X
H
H
L
Idle  
Row  
Activating,  
Active, or  
Precharging  
Read  
READ (Select column and start READ burst)(7)  
WRITE (Select column and start WRITE burst)(7)  
PRECHARGE  
H
H
L
L
H
H
L
L
ACTIVE (Select and activate row)  
L
H
H
L
(Auto  
READ (Select column and start new READ burst)(7,10)  
WRITE (Select column and start WRITE burst)(7,11)  
PRECHARGE(9)  
H
H
L
Precharge  
Disabled)  
Write  
L
H
H
L
L
ACTIVE (Select and activate row)  
L
H
H
L
(Auto  
READ (Select column and start READ burst)(7,12)  
WRITE (Select column and start new WRITE burst)(7,13)  
PRECHARGE(9)  
H
H
L
Precharge  
Disabled)  
Read  
L
H
H
L
L
ACTIVE (Select and activate row)  
L
H
H
L
(With Auto  
Precharge)  
READ (Select column and start new READ burst)(7,8,14)  
WRITE (Select column and start WRITE burst)(7,8,15)  
PRECHARGE(9)  
H
H
L
L
H
H
L
L
Write  
ACTIVE (Select and activate row)  
L
H
H
L
(With Auto  
Precharge)  
READ (Select column and start READ burst)(7,8,16)  
WRITE (Select column and start new WRITE burst)(7,8,17)  
PRECHARGE(9)  
H
H
L
L
H
L
NOTE:  
1. This table applies when CKE n-1 was HIGH and CKE n is HIGH (Truth Table - CKE) and after tXSR has been met (if the previous  
state was self refresh).  
2. This table describes alternate bank operation, except where noted; i.e., the current state is for bank n and the commands shown  
are those allowed to be issued to bank m (assuming that bank m is in such a state that the given command is allowable). Exceptions are  
covered in the notes below.  
3. Currentstatedefinitions:  
Idle: The bank has been precharged, and tRP has been met.  
Row Active: A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and no register  
accesses are in progress.  
Read: A READ burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated.  
Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated.  
Readw/Auto  
PrechargeEnabled: Starts with registration of a READ command with auto precharge enabled, and ends when tRP has been met.  
Once tRP is met, the bank will be in the idle state.  
Writew/Auto  
PrechargeEnabled: Starts with registration of a WRITE command with auto precharge enabled, and ends when tRP has been  
met. Once tRP is met, the bank will be in the idle state.  
4. AUTO REFRESH, SELF REFRESH and LOAD MODE REGISTER commands may only be issued when all banks are idle.  
5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state only.  
6. All states and sequences not shown are illegal or reserved.  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
9
12/01/01  
®
IS42S16400L  
ISSI  
7. READs or WRITEs to bank m listed in the Command (Action) column include READs or WRITEs with auto precharge enabled  
and READs or WRITEs with auto precharge disabled.  
8. CONCURRENT AUTO PRECHARGE: Bank n will initiate the AUTO PRECHARGE command when its burst has been inter-  
rupted by bank m’s burst.  
9. Burst in bank n continues as initiated.  
10. For a READ without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the  
READ on bank n, CAS latency later (Consecutive READ Bursts).  
11. For a READ without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt  
the READ on bank n when registered (READ to WRITE). DQM should be used one clock prior to the WRITE command to prevent  
buscontention.  
12. For a WRITE without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt  
the WRITE on bank n when registered (WRITE to READ), with the data-out appearing CAS latency later. The last valid WRITE to  
bank n will be data-in registered one clock prior to the READ to bank m.  
13. For a WRITE without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt  
the WRITE on bank n when registered (WRITE to WRITE). The last valid WRITE to bank n will be data-in registered one clock  
prior to the READ to bank m.  
14. For a READ with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the  
READ on bank n, CAS latency later. The PRECHARGE to bank n will begin when the READ to bank m is registered (Fig CAP 1).  
15. For a READ with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the  
READ on bank n when registered. DQM should be used two clocks prior to the WRITE command to prevent bus contention. The  
PRECHARGE to bank n will begin when the WRITE to bank m is registered (Fig CAP 2).  
16. For a WRITE with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the  
WRITE on bank n when registered, with the data-out appearing CAS latency later. The PRECHARGE to bank n will begin after  
tWR is met, where tWR begins when the READ to bank m is registered. The last valid WRITE to bank n will be data-in registered  
one clock prior to the READ to bank m (Fig CAP 3).  
17. For a WRITE with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the  
WRITE on bank n when registered. The PRECHARGE to bank n will begin after tWR is met, where t WR begins when the WRITE  
to bank m is registered. The last valid WRITE to bank n will be data registered one clock prior to the WRITE to bank m (Fig CAP 4).  
10  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
ABSOLUTE MAXIMUM RATINGS(1)  
Symbol  
Parameters  
Rating  
Unit  
VCC MAX  
VCCQ MAX  
VIN  
Maximum Supply Voltage  
Maximum Supply Voltage for Output Buffer  
Input Voltage  
–1.0 to +4.6  
–1.0 to +4.6  
–1.0 to +4.6  
–1.0 to +4.6  
1
V
V
V
VOUT  
Output Voltage  
V
PD MAX  
ICS  
Allowable Power Dissipation  
Output Shorted Current  
W
mA  
°C  
50  
TOPR  
Operating Temperature  
Com.  
Ind.  
0 to +70  
–40 to +85  
TSTG  
Storage Temperature  
–55 to +150  
°C  
DC RECOMMENDED OPERATING CONDITIONS(2) (At TA = 0 to +70°C)  
Symbol  
Parameter  
Min.  
Typ.  
Max.  
Unit  
VCC, VCCQ  
VIH  
Supply Voltage  
3.0  
2.0  
3.3  
—
3.6  
VCC + 0.3  
+0.8  
V
V
V
Input High Voltage  
Input Low Voltage  
VIL  
-0.3  
—
CAPACITANCE CHARACTERISTICS(1,2) (At TA = 0 to +25°C, Vcc = VccQ = 3.3 ± 0.3V, f = 1 MHz)  
Symbol  
Parameter  
Typ.  
Max.  
Unit  
CIN1  
CIN2  
CI/O  
Input Capacitance: A0-A11, BA0, BA1  
—
—
—
4
4
5
pF  
pF  
pF  
Input Capacitance: (CLK, CKE, CS, RAS, CAS, WE, LDQM, UDQM)  
Data Input/Output Capacitance: I/O0-I/O15  
Notes:  
1. Stress greater than 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 above those indicated in the operational  
sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect  
reliability.  
2. All voltages are referenced to GND.  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
11  
12/01/01  
®
IS42S16400L  
ISSI  
DC ELECTRICAL CHARACTERISTICS (Recommended Operation Conditions unless otherwise noted.)  
Symbol Parameter  
Test Condition  
Speed Min.  
Max.  
Unit  
I
IL  
Input Leakage Current  
0V ≤ VIN ≤ VCC, with pins other than  
–5  
5
µA  
the tested pin at 0V  
I
OL  
Output Leakage Current  
Output High Voltage Level  
Output Low Voltage Level  
Operating Current(1,2)  
Output is disabled, 0V ≤ VOUT ≤ VCC  
–5  
2.4  
—
5
µA  
V
V
V
OH  
OL  
I
I
OUT = –2 mA  
—
OUT = +2 mA  
0.4  
V
I
CC1  
One Bank Operation,  
Burst Length=1  
CAS latency = 3  
Com.  
-6  
-7  
-7  
-10  
-10  
—
—
—
—
—
70  
60  
75  
60  
75  
mA  
mA  
mA  
mA  
mA  
t
I
RC ≥ tRC (min.)  
OUT = 0mA  
Ind.  
Com.  
Ind.  
I
I
CC2P  
Precharge Standby Current CKE ≤ VIL  
(
MAX  
)
t
t
CK = tCK  
(
MIN)  
Com.  
Ind.  
Com.  
Ind.  
—
—
—
—
—
—
—
—
3
4
2
3
mA  
mA  
mA  
mA  
CC2PS  
(In Power-Down Mode)  
CK = ∞  
I
I
CC2N  
Precharge Standby Current CKE ≥ VIH  
(In Non Power-Down Mode)  
(
MIN  
)
t
t
CK = tCK  
CK = ∞  
(
(
MIN  
)
)
—
—
—
—
—
—
30  
10  
15  
mA  
mA  
mA  
CC2NS  
Com.  
Ind.  
I
I
CC3P  
Active Standby Current  
(In Power-Down Mode)  
CKE ≤ VIL  
CKE ≥ VIH  
(
MAX  
)
t
CK = tCK  
MIN  
Com.  
Ind.  
Com.  
Ind.  
—
—
—
—
—
—
—
—
3
7
3
5
mA  
mA  
mA  
mA  
Ind.  
t
CC3PS  
CK = ∞  
I
I
CC3N  
Active Standby Current  
(
MIN)  
t
t
CK = tCK  
CK = ∞  
(
MIN)  
—
—
—
—
—
—
40  
20  
25  
mA  
mA  
mA  
CC3NS  
(In Non Power-Down Mode)  
Com.  
Ind.  
I
I
I
CC4  
CC5  
CC6  
Operating Current  
(In Burst Mode)(1)  
t
I
CK = tCK  
OUT = 0mA  
(
MIN  
)
CAS latency = 3  
Com.  
-6  
-7  
-7  
-10  
-10  
—
—
—
—
—
130  
100  
120  
80  
mA  
mA  
mA  
mA  
mA  
Ind.  
Com.  
Ind.  
100  
CAS latency = 2  
-6  
-7  
-7  
-10  
-10  
—
—
—
—
—
130  
100  
120  
80  
mA  
mA  
mA  
mA  
mA  
Com.  
Ind.  
Com.  
Ind.  
100  
Auto-Refresh Current  
t
RC = tRC  
(
MIN  
)
CAS latency = 3  
-6  
-7  
-7  
-10  
-10  
—
—
—
—
—
150  
130  
150  
110  
130  
mA  
mA  
mA  
mA  
mA  
Com.  
Ind.  
Com.  
Ind.  
CAS latency = 2  
-6  
-7  
-7  
-10  
-10  
—
—
—
—
—
130  
100  
120  
80  
mA  
mA  
mA  
mA  
mA  
Com.  
Ind.  
Com.  
Ind.  
100  
Self-Refresh Current  
CKE ≤ 0.2V  
—
—
420  
µA  
Notes:  
1. These are the values at the minimum cycle time. Since the currents are transient, these values decrease as the cycle time  
increases. Also note that a bypass capacitor of at least 0.01 µF should be inserted between Vcc and GND for each memory chip  
to suppress power supply voltage noise (voltage drops) due to these transient currents.  
2. Icc1 and Icc4 depend on the output load. The maximum values for Icc1 and Icc4 are obtained with the output open state.  
12  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
AC ELECTRICAL CHARACTERISTICS (1,2,3)  
-6  
-7  
-10  
Min.  
Symbol Parameter  
Min.  
Max.  
Min.  
Max.  
Max  
Units  
tCK3  
tCK2  
Clock Cycle Time  
CAS Latency = 3  
CAS Latency = 2  
6
8
—
—
7
10  
—
—
10  
10  
—
—
ns  
ns  
tAC3  
tAC2  
Access Time From CLK(4)  
CAS Latency = 3  
CAS Latency = 2  
—
—
5.5  
6
—
—
6
6
—
—
7
9
ns  
ns  
tCHI  
tCL  
CLK HIGH Level Width  
CLK LOW Level Width  
Output Data Hold Time  
2
2
—
—
2.5  
2.5  
—
—
3.5  
3.5  
—
—
ns  
ns  
tOH3  
tOH2  
CAS Latency = 3  
CAS Latency = 2  
2.5  
2.5  
—
—
2.5  
2.5  
—
—
2.5  
2.5  
—
—
ns  
ns  
tLZ  
OutputLOWImpedanceTime  
0
—
0
—
0
—
ns  
tHZ3  
tHZ2  
OutputHIGHImpedanceTime(5) CAS Latency = 3  
CAS Latency = 2  
—
—
5.5  
6
—
—
6
6
—
—
7
9
ns  
ns  
tDS  
Input Data Setup Time  
1.5  
0.8  
1.5  
0.8  
1.5  
0.8  
—
—
1.5  
0.8  
1.5  
0.8  
1.5  
0.8  
—
—
2.0  
1
—
—
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
tDH  
Input Data Hold Time  
tAS  
Address Setup Time  
—
—
2.0  
1
—
tAH  
Address Hold Time  
—
—
—
tCKS  
tCKH  
tCKA  
tCS  
CKE Setup Time  
—
—
2.0  
1
—
CKE Hold Time  
—
—
—
CKE to CLK Recovery Delay Time  
Command Setup Time (CS, RAS, CAS, WE, DQM)  
Command Hold Time (CS, RAS, CAS, WE, DQM)  
Command Period (REF to REF / ACT to ACT)  
Command Period (ACT to PRE)  
Command Period (PRE to ACT)  
Active Command To Read / Write Command Delay Time  
Command Period (ACT [0] to ACT[1])  
1CLK+3  
1.5  
0.8  
60  
—
1CLK+3  
1.5  
0.8  
63  
—
1CLK+3  
2.0  
1
—
—
—
—
tCH  
—
—
—
tRC  
—
—
70  
—
tRAS  
tRP  
35  
120,000  
—
37  
120,000  
—
44  
120,000  
—
15  
15  
18  
tRCD  
tRRD  
tDPL3  
15  
—
15  
—
18  
—
14  
—
14  
—
15  
—
Input Data To Precharge  
CommandDelaytime  
CAS Latency = 3  
2CLK  
—
2CLK  
—
2CLK  
—
tDPL2  
tDAL3  
CAS Latency = 2  
2CLK  
—
—
2CLK  
—
—
2CLK  
—
—
ns  
ns  
Input Data To Active / Refresh CAS Latency = 3  
CommandDelaytime(DuringAuto-Precharge)  
CAS Latency = 2  
2CLK+tRP  
2CLK+tRP  
2CLK+tRP  
tDAL2  
tT  
2CLK+tRP  
—
10  
64  
2CLK+tRP  
—
10  
64  
2CLK+tRP  
—
10  
64  
ns  
ns  
TransitionTime  
1
1
1
tREF  
RefreshCycleTime(4096)  
—
—
—
ms  
Notes:  
1. When power is first applied, memory operation should be started 100 µs after Vcc and VccQ reach their stipulated voltages. Also  
note that the power-on sequence must be executed before starting memory operation.  
2. Measured with tT = 1 ns.  
3. The reference level is 1.4 V when measuring input signal timing. Rise and fall times are measured between VIH (min.) and VIL  
(max.).  
4. Access time is measured at 1.4V with the load shown in the figure below.  
5. The time tHZ (max.) is defined as the time required for the output voltage to transition by ± 200 mV from VOH (min.) or VOL (max.)  
when the output is in the high impedance state.  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
13  
12/01/01  
®
IS42S16400L  
ISSI  
OPERATING FREQUENCY / LATENCY RELATIONSHIPS  
SYMBOL PARAMETER  
-6  
6
-7  
7
-10.  
10  
100  
1
UNITS  
ns  
—
Clock Cycle Time  
—
Operating Frequency  
166  
1
133  
1
MHz  
tCCD  
tCKED  
tPED  
tDQD  
tDQM  
tDQZ  
tDWD  
tDAL  
tDPL  
tBDL  
tCDL  
tRDL  
tMRD  
READ/WRITE command to READ/WRITE command  
CKE to clock disable or power-down entry mode  
CKE to clock enable or power-down exit setup mode  
DQM to input data delay  
cycle  
cycle  
cycle  
cycle  
cycle  
cycle  
cycle  
cycle  
cycle  
cycle  
cycle  
cycle  
cycle  
1
1
1
1
1
1
0
0
0
DQM to data mask during WRITEs  
DQM to data high-impedance during READs  
WRITE command to input data delay  
Data-in to ACTIVE command  
0
0
0
2
2
2
0
0
0
5
5
4
Data-in to PRECHARGE command  
Last data-in to burst STOP command  
Last data-in to new READ/WRITE command  
Last data-in to PRECHARGE command  
2
2
2
1
1
1
1
1
1
2
2
2
LOAD MODE REGISTER command  
to ACTIVE or REFRESH command  
2
2
2
tROH  
cycle  
Data-out to high-impedance from  
CL = 3  
CL = 2  
3
2
3
2
3
2
PRECHARGE command  
AC TEST CONDITIONS (Input/Output Reference Level: 1.4V)  
Input Load  
Output Load  
t
CK  
t
CHI  
t
CL  
2.0V  
1.4V  
CLK  
50 Ω  
0.8V  
I/O  
+1.4V  
t
CS  
t
CH  
2.0V  
1.4V  
50 pF  
INPUT  
0.8V  
t
AC  
t
OH  
OUTPUT  
1.4V  
1.4V  
14  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
Initialization  
FUNCTIONALDESCRIPTION  
SDRAMs must be powered up and initialized in a  
predefined manner.  
The 64Mb SDRAMs (1 Meg x 16 x 4 banks) are quad-bank  
DRAMs which operate at 3.3V and include a synchronous  
interface (all signals are registered on the positive edge of  
the clock signal, CLK). Each of the 16,777,216-bit banks  
is organized as 4,096 rows by 256 columns by 16 bits.  
The 64M SDRAM is initialized after the power is applied  
to VCC and VCCQ (simultaneously) and the clock is stable.  
A 100µs delay is required prior to issuing any command  
other than a COMMAND INHIBIT or aNOP. The COMMAND  
INHIBIT or NOP may be applied during the 100us period  
and continue should at least through the end of the period.  
Read and write accesses to the SDRAM are burst oriented;  
accesses start at a selected location and continue for a  
programmed number of locations in a programmed  
sequence. Accesses begin with the registration of an  
ACTIVE command which is then followed by a READ or  
WRITE command. The address bits registered coincident  
with the ACTIVE command are used to select the bank  
androwtobeaccessed(BA0andBA1selectthebank,A0-A11  
select the row). The address bits (A0-A7) registered coincident  
with the READ or WRITE command are used to select the  
starting column location for the burst access.  
With at least one COMMAND INHIBIT or NOP command  
havingbeenapplied,aPRECHARGEcommandshouldbe  
applied once the 100µs delay has been satisfied. All  
banks must be precharged. This will leave all banks in an  
idle idle state where two AUTO REFRESH cycles must be  
performed. After the AUTO REFRESH cycles are complete,  
theSRDRAMisthenreadyformoderegisterprogramming.  
The mode register should be loaded prior to applying any  
operational command because it will power up in an  
unknown state.  
Prior to normal operation, the SDRAM must be initialized.  
The following sections provide detailed information covering  
device initialization, register definition, command  
descriptions and device operation.  
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®
IS42S16400L  
ISSI  
until it is programmed again or the device loses power.  
REGISTER DEFINITION  
Mode Register  
The mode register is used to define the specific mode of  
operation of the SDRAM. This definition includes the  
selection of a burst length, a burst type, a CAS\ latency,  
an operating mode and a write burst mode, as shown in  
MODE REGISTER DEFINITION.  
Mode register bits M0-M2 specify the burst length, M3  
specifiesthetypeofburst(sequentialorinterleaved), M4-M6  
specify the CAS latency, M7 and M8 specify the operating  
mode, M9 specifies the WRITE burst mode, and M10 and  
M11 are reserved for future use.  
The mode register must be loaded when all banks are idle,  
and the controller must wait the specified time before  
initiating the subsequent operation. Violating either of  
these requirements will result in unspecified operation.  
The mode register is programmed via the LOAD MODE  
REGISTER command and will retain the stored information  
MODE REGISTER DEFINITION  
Address Bus  
A11 A10 A9  
A8  
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
Mode Register (Mx)  
Reserved(1)  
Burst Length  
M2 M1 M0  
M3=0  
M3=1  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
2
4
8
1
2
4
8
Reserved Reserved  
Reserved Reserved  
Reserved Reserved  
Full Page Reserved  
Burst Type  
M3  
Type  
0
Sequential  
1
Interleaved  
Latency Mode  
M6 M5 M4  
CAS Latency  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Reserved  
Reserved  
2
3
Reserved  
Reserved  
Reserved  
Reserved  
Operating Mode  
M8 M7 M6-M0 Mode  
0
0
Defined Standard Operation  
All Other States Reserved  
—
—
—
Write Burst Mode  
M9  
0
Mode  
Programmed Burst Length  
Single Location Access  
1. To ensure compatibility with future devices,  
should program M11, M10 = "0, 0"  
1
16  
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ISSI  
Burst Length  
All accesses for that burst take place within this block,  
meaning that the burst will wrap within the block if a  
boundary is reached. The block is uniquely selected by  
A1-A7 (x16) when the burst length is set to two; by A2-A7  
(x16) when the burst length is set to four; and by A3-A7  
(x16) when the burst length is set to eight. The remaining  
(least significant) address bit(s) is (are) used to select the  
starting location within the block. Full-page bursts wrap  
within the page if the boundary is reached.  
Read and write accesses to the SDRAM are burst ori-  
ented, with the burst length being programmable, as  
shown in MODE REGISTER DEFINITION. The burst  
length determines the maximum number of column loca-  
tions that can be accessed for a given READ or WRITE  
command. Burst lengths of 1, 2, 4 or 8 locations are  
available for both the sequential and the interleaved burst  
types, and a full-page burst is available for the sequential  
type. The full-page burst is used in conjunction with the  
BURST TERMINATE command to generate arbitrary  
burst lengths.  
Burst Type  
Accesses within a given burst may be programmed to be  
either sequential or interleaved; this is referred to as the  
burst type and is selected via bit M3.  
Reserved states should not be used, as unknown opera-  
tion or incompatibility with future versions may result.  
The ordering of accesses within a burst is determined by  
the burst length, the burst type and the starting column  
address, as shown in BURST DEFINITION table.  
When a READ or WRITE command is issued, a block of  
columns equal to the burst length is effectively selected.  
BURST DEFINITION  
Burst  
StartingColumn  
Address  
Order of Accesses Within a Burst  
Length  
Type=Sequential  
Type=Interleaved  
A0  
2
4
0
1
0-1  
1-0  
0-1  
1-0  
A1  
0
A0  
0
0-1-2-3  
1-2-3-0  
2-3-0-1  
3-0-1-2  
0-1-2-3  
1-0-3-2  
2-3-0-1  
3-2-1-0  
0
1
1
0
1
1
A2  
A1  
0
A0  
0
0
0-1-2-3-4-5-6-7  
1-2-3-4-5-6-7-0  
2-3-4-5-6-7-0-1  
3-4-5-6-7-0-1-2  
4-5-6-7-0-1-2-3  
5-6-7-0-1-2-3-4  
6-7-0-1-2-3-4-5  
7-0-1-2-3-4-5-6  
0-1-2-3-4-5-6-7  
1-0-3-2-5-4-7-6  
2-3-0-1-6-7-4-5  
3-2-1-0-7-6-5-4  
4-5-6-7-0-1-2-3  
5-4-7-6-1-0-3-2  
6-7-4-5-2-3-0-1  
7-6-5-4-3-2-1-0  
Not Supported  
0
0
1
0
1
0
8
0
1
1
1
0
0
1
0
1
1
1
1
0
1
1
Full  
Page  
(y)  
n = A0-A7  
Cn, Cn + 1, Cn + 2  
Cn + 3, Cn + 4...  
…Cn - 1,  
(location0-y)  
Cn…  
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IS42S16400L  
ISSI  
reserved for future use and/or test modes. The programmed  
CAS Latency  
burst length applies to both READ and WRITE bursts.  
The CAS latency is the delay, in clock cycles, between the  
registration of a READ command and the availability of the first  
pieceofoutputdata.Thelatencycanbesettotwoorthreeclocks.  
Test modes and reserved states should not be used  
because unknown operation or incompatibility with future  
versions may result.  
If a READ command is registered at clock edge n, and the  
latency is m clocks, the data will be available by clock  
edge n + m. The DQs will start driving as a result of the  
clock edge one cycle earlier (n + m - 1), and provided that  
the relevant access times are met, the data will be valid  
by clock edge n + m. For example, assuming that the  
clock cycle time is such that all relevant access times are  
met, if a READ command is registered at T0 and the  
latency is programmed to two clocks, the DQs will start  
driving after T1 and the data will be valid by T2, as shown  
in CAS Latency diagrams. The Allowable Operating  
Frequency table indicates the operating frequencies at  
which each CAS latency setting can be used.  
Write Burst Mode  
When M9 = 0, the burst length programmed via M0-M2  
appliestobothREADandWRITEbursts;whenM9=1, the  
programmed burst length applies to READ bursts, but  
write accesses are single-location (nonburst) accesses.  
CAS Latency  
Allowable Operating Frequency (MHz)  
Speed  
6
CASLatency=2  
CASLatency=3  
Reserved states should not be used as unknown operation  
or incompatibility with future versions may result.  
—
—
166  
133  
—
7
Operating Mode  
ThenormaloperatingmodeisselectedbysettingM7andM8  
to zero; the other combinations of values for M7 and M8 are  
10  
100  
CAS Latency  
T0  
T1  
T2  
T3  
CLK  
READ  
NOP  
NOP  
COMMAND  
DQ  
tAC  
DOUT  
tLZ  
tOH  
CAS Latency - 2  
T0  
T1  
T2  
T3  
T4  
CLK  
READ  
NOP  
NOP  
NOP  
COMMAND  
DQ  
tAC  
DOUT  
tLZ  
tOH  
CAS Latency - 3  
DON'T CARE  
UNDEFINED  
18  
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®
IS42S16400L  
ISSI  
OPERATION  
ActivatingSpecificRowWithinSpecificBank  
BANK/ROW ACTIVATION  
Before any READ or WRITE commands can be issued to  
a bank within the SDRAM, a row in that bank must be  
“opened.” This is accomplished via the ACTIVE command,  
which selects both the bank and the row to be activated  
(see Activating Specific Row Within Specific Bank).  
CLK  
HIGH - Z  
CKE  
Afteropeningarow(issuinganACTIVEcommand), aREAD  
or WRITE command may be issued to that row, subject to  
the tRCD specification. Minimum tRCD should be divided by  
the clock period and rounded up to the next whole number  
to determine the earliest clock edge after the ACTIVE  
command on which a READ or WRITE command can be  
entered. For example, a tRCD specification of 20ns with a  
125 MHz clock (8ns period) results in 2.5 clocks, rounded  
to 3. This is reflected in the following example, which  
covers any case where 2 < [tRCD (MIN)/tCK] ≤ 3. (The  
same procedure is used to convert other specification  
limits from time units to clock cycles).  
CS  
RAS  
CAS  
WE  
A0-A11  
BA0, BA1  
ROW ADDRESS  
BANK ADDRESS  
A subsequent ACTIVE command to a different row in the  
same bank can only be issued after the previous active  
row has been “closed” (precharged). The minimum time  
interval between successive ACTIVE commands to the  
same bank is defined by tRC.  
A subsequent ACTIVE command to another bank can be  
issued while the first bank is being accessed, which  
results in a reduction of total row-access overhead. The  
minimum time interval between successive ACTIVE com-  
mands to different banks is defined by tRRD.  
Example: Meeting tRCD (MIN) when 2 < [tRCD (min)/tCK] ≤ 3  
T0  
T1  
T2  
T3  
T4  
CLK  
READ or  
WRITE  
ACTIVE  
NOP  
NOP  
COMMAND  
tRCD  
DON'T CARE  
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IS42S16400L  
ISSI  
READS  
READ COMMAND  
READ bursts are initiated with a READ command, as  
shown in the READ COMMAND diagram.  
CLK  
The starting column and bank addresses are provided with  
the READ command, and auto precharge is either enabled  
or disabled for that burst access. If auto precharge is  
enabled, the row being accessed is precharged at the  
completion of the burst. For the generic READ commands  
used in the following illustrations, auto precharge is disabled.  
HIGH-Z  
CKE  
CS  
RAS  
During READ bursts, the valid data-out element from the  
starting column address will be available following the  
CAS latency after the READ command. Each subsequent  
data-out element will be valid by the next positive clock  
edge. The CAS Latency diagram shows general timing  
for each possible CAS latency setting.  
CAS  
WE  
Upon completion of a burst, assuming no other commands  
have been initiated, the DQs will go High-Z. A full-page  
burst will continue until terminated. (At the end of the page,  
it will wrap to column 0 and continue.)  
COLUMN ADDRESS  
AUTO PRECHARGE  
A0-A7  
A8, A9, A11  
A10  
Data from any READ burst may be truncated with a  
subsequent READ command, and data from a fixed-length  
READ burst may be immediately followed by data from a  
READ command. In either case, a continuous flow of data  
can be maintained. The first data element from the new  
burst follows either the last element of a completed burst or  
the last desired data element of a longer burst which is  
being truncated.  
NO PRECHARGE  
BANK ADDRESS  
BA0, BA1  
The new READ command should be issued x cycles  
before the clock edge at which the last desired data  
element is valid, where x equals the CAS latency minus  
one. This is shown in Consecutive READ Bursts for CAS  
latencies of two and three; data element n + 3 is either the  
last of a burst of four or the last desired of a longer burst.  
The 64Mb SDRAM uses a pipelined architecture and  
therefore does not require the 2n rule associated with a  
prefetch architecture. A READ command can be initiated  
on any clock cycle following a previous READ command.  
Full-speed random read accesses can be performed to the  
same bank, as shown in Random READ Accesses, or each  
subsequent READ may be performed to a different bank.  
The DQM input is used to avoid I/O contention, as shown  
in Figures RW1 and RW2. The DQM signal must be  
asserted (HIGH) at least two clocks prior to the WRITE  
command (DQM latency is two clocks for output buffers)  
to suppress data-out from the READ. Once the WRITE  
command is registered, the DQs will go High-Z (or remain  
High-Z), regardless of the state of the DQM signal,  
provided the DQM was active on the clock just prior to the  
WRITE command that truncated the READ command. If  
not, the second WRITE will be an invalid WRITE. For  
example, if DQM was LOW during T4 in Figure RW2, then  
the WRITEs at T5 and T7 would be valid, while the WRITE  
at T6 would be invalid.  
Data from any READ burst may be truncated with a  
subsequent WRITE command, and data from a fixed-length  
READ burst may be immediately followed by data from a  
WRITE command (subject to bus turnaround limitations).  
The WRITE burst may be initiated on the clock edge  
immediately following the last (or last desired) data  
element from the READ burst, provided that I/O contention  
can be avoided. In a given system design, there may be  
a possibility that the device driving the input data will go  
Low-Z before the SDRAM DQs go High-Z. In this case, at  
least a single-cycle delay should occur between the last  
read data and the WRITE command.  
The DQM signal must be de-asserted prior to the WRITE  
command (DQM latency is zero clocks for input buffers)  
to ensure that the written data is not masked. Figure RW1  
shows the case where the clock frequency allows for bus  
contention to be avoided without adding a NOP cycle, and  
Figure RW2 shows the case where the additional NOP is  
needed.  
Afixed-lengthREADburstmaybefollowedby, ortruncated  
with, aPRECHARGE commandtothesamebank(provided  
that auto precharge was not activated), and a full-page burst  
may be truncated with a PRECHARGE command to the  
20  
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®
IS42S16400L  
ISSI  
samebank.ThePRECHARGEcommandshouldbeissued  
x cycles before the clock edge at which the last desired  
data element is valid, where x equals the CAS latency  
minus one. This is shown in the READ to PRECHARGE  
diagram for each possible CAS latency; data element n +  
3 is either the last of a burst of four or the last desired of a  
longer burst. Following the PRECHARGE command, a  
subsequent command to the same bank cannot be issued  
until tRP is met. Note that part of the row precharge time is  
hidden during the access of the last data element(s).  
PRECHARGE command is that it requires that the com-  
mand and address buses be available at the appropriate  
time to issue the command; the advantage of the  
PRECHARGE command is that it can be used to truncate  
fixed-length or full-page bursts.  
Full-page READ bursts can be truncated with the BURST  
TERMINATE command, and fixed-length READ bursts  
may be truncated with a BURST TERMINATE command,  
provided that auto precharge was not activated. The  
BURSTTERMINATEcommandshouldbeissuedxcycles  
before the clock edge at which the last desired data  
element is valid, where x equals the CAS latency minus  
one. This is shown in the READ Burst Termination  
diagram for each possible CAS latency; data element n +  
3 is the last desired data element of a longer burst.  
In the case of a fixed-length burst being executed to  
completion, a PRECHARGE command issued at the  
optimum time (as described above) provides the same  
operation that would result from the same fixed-length  
burst with auto precharge. The disadvantage of the  
CAS Latency  
T0  
T1  
T2  
T3  
CLK  
READ  
NOP  
NOP  
COMMAND  
DQ  
tAC  
DOUT  
tLZ  
tOH  
CAS Latency - 2  
T0  
T1  
T2  
T3  
T4  
CLK  
READ  
NOP  
NOP  
NOP  
COMMAND  
DQ  
tAC  
DOUT  
tLZ  
tOH  
CAS Latency - 3  
DON'T CARE  
UNDEFINED  
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IS42S16400L  
ISSI  
Consecutive READ Bursts  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
CLK  
COMMAND  
ADDRESS  
DQ  
READ  
NOP  
NOP  
NOP  
READ  
NOP  
NOP  
x=1 cycle  
BANK,  
COL n  
BANK,  
COL b  
DOUT  
n
DOUT n+1  
DOUT n+2  
DOUT n+3  
DOUT  
b
CAS Latency - 2  
DON'T CARE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
CLK  
COMMAND  
READ  
NOP  
NOP  
NOP  
READ  
NOP  
x = 2 cycles  
NOP  
NOP  
BANK,  
COL n  
BANK,  
COL b  
ADDRESS  
DQ  
DOUT  
n
DOUT n+1  
DOUT n+2  
DOUT n+3  
DOUT  
b
CAS Latency - 3  
DON'T CARE  
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IS42S16400L  
ISSI  
Random READ Accesses  
T0  
T1  
T2  
T3  
T4  
T5  
CLK  
COMMAND  
ADDRESS  
DQ  
READ  
READ  
READ  
READ  
NOP  
NOP  
BANK,  
COL n  
BANK,  
COL b  
BANK,  
COL m  
BANK,  
COL x  
DOUT  
n
DOUT  
b
DOUT  
m
DOUT  
x
CAS Latency - 2  
DON'T CARE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
CLK  
COMMAND  
ADDRESS  
DQ  
READ  
READ  
READ  
READ  
NOP  
NOP  
NOP  
BANK,  
COL n  
BANK,  
COL b  
BANK,  
COL m  
BANK,  
COL x  
DOUT  
n
DOUT  
b
DOUT  
m
DOUT  
x
CAS Latency - 3  
DON'T CARE  
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IS42S16400L  
ISSI  
RW1 - READ to WRITE  
T0  
T1  
T2  
T3  
T4  
CLK  
DQM  
COMMAND  
ADDRESS  
DQ  
READ  
NOP  
NOP  
NOP  
WRITE  
BANK,  
COL n  
BANK,  
COL b  
t
HZ  
DOUT  
n
DIN  
b
t
DS  
DON'T CARE  
RW2 - READ to WRITE With Extra Clock Cycle  
T0  
T1  
T2  
T3  
T4  
T5  
CLK  
DQM  
COMMAND  
ADDRESS  
DQ  
READ  
NOP  
NOP  
NOP  
NOP  
WRITE  
BANK,  
COL n  
BANK,  
COL b  
t
HZ  
DOUT  
n
D
IN  
b
t
DS  
DON'T CARE  
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IS42S16400L  
ISSI  
READ to PRECHARGE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
CLK  
t
RP  
PRECHARGE  
COMMAND  
ADDRESS  
DQ  
READ  
NOP  
NOP  
NOP  
NOP  
NOP  
ACTIVE  
x = 1 cycle  
BANK a,  
COL n  
BANK  
(a or all)  
BANK a,  
ROW  
DOUT  
n
DOUT n+1  
DOUT n+2  
DOUT n+3  
CAS Latency - 2  
DON'T CARE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
CLK  
COMMAND  
ADDRESS  
DQ  
t
RP  
PRECHARGE  
READ  
NOP  
NOP  
NOP  
NOP  
x = 2 cycles  
NOP  
ACTIVE  
BANK,  
COL n  
BANK,  
COL b  
BANK a,  
ROW  
DOUT  
n
DOUT n+1  
D
OUT n+2  
DOUT n+3  
CAS Latency - 3  
DON'T CARE  
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®
IS42S16400L  
ISSI  
READ Burst Termination  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
CLK  
BURST  
TERMINATE  
COMMAND  
ADDRESS  
DQ  
READ  
NOP  
NOP  
NOP  
NOP  
NOP  
x = 1 cycle  
BANK a,  
COL n  
DOUT  
n
DOUT n+1  
DOUT n+2  
DOUT n+3  
CAS Latency - 2  
DON'T CARE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
CLK  
COMMAND  
ADDRESS  
DQ  
BURST  
TERMINATE  
READ  
NOP  
NOP  
NOP  
NOP  
x = 2 cycles  
NOP  
NOP  
BANK,  
COL n  
DOUT  
n
DOUT n+1  
DOUT n+2  
DOUT n+3  
CAS Latency - 3  
DON'T CARE  
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IS42S16400L  
ISSI  
An example is shown in WRITE to WRITE diagram. Data  
n + 1 is either the last of a burst of two or the last desired  
of a longer burst. The 64Mb SDRAM uses a pipelined  
architecture and therefore does not require the 2n rule  
associated with a prefetch architecture. A WRITE command  
can be initiated on any clock cycle following a previous  
WRITE command. Full-speed random write accesses  
within a page can be performed to the same bank, as  
shown in Random WRITE Cycles, or each subsequent  
WRITE may be performed to a different bank.  
WRITEs  
WRITE bursts are initiated with a WRITE command, as  
shown in WRITE Command diagram.  
WRITE Command  
CLK  
HIGH - Z  
CKE  
Data for any WRITE burst may be truncated with a  
subsequent READ command, and data for a fixed-length  
WRITE burst may be immediately followed by a subsequent  
READ command. Once the READ com mand is regis-  
tered, the data inputs will be ignored, and WRITEs will not  
be executed. An example is shown in WRITE to READ.  
Data n + 1 is either the last of a burst of two or the last  
desired of a longer burst.  
CS  
RAS  
CAS  
WE  
Data for a fixed-length WRITE burst may be fol lowed by,  
or truncated with, a PRECHARGE command to the same  
bank (provided that auto precharge was not activated),  
and a full-page WRITE burst may be truncated with a  
PRECHARGE command to the same bank. The  
PRECHARGE command should be issued tWR after the  
clock edge at which the last desired input data element is  
registered. The auto precharge mode requires a tWR of at  
least one clock plus time, regardless of frequency. In  
addition, when truncating a WRITE burst, the DQM signal  
must be used to mask input data for the clock edge prior  
to, and the clock edge coincident with, the PRECHARGE  
command. An example is shown in the WRITE to  
PRECHARGE diagram.Datan+1iseitherthelastofaburst  
of two or the last desired of a longer burst. Following the  
PRECHARGE command, a subsequent command to the  
same bank cannot be issued until tRP is met.  
COLUMN ADDRESS  
AUTO PRECHARGE  
A0-A7  
A8, A9, A11  
A10  
NO PRECHARGE  
BANK ADDRESS  
BA0, BA1  
The starting column and bank addresses are provided with  
theWRITEcommand,andautoprechargeiseitherenabled  
ordisabledforthataccess. Ifautoprechargeisenabled, the  
row being accessed is precharged at the completion of the  
burst. For the generic WRITE commands used in the  
following illustrations, auto precharge is disabled.  
In the case of a fixed-length burst being executed to  
completion, a PRECHARGE command issued at the opti-  
mum time (as described above) provides the same operation  
that would result from the same fixed-length burst with auto  
precharge. The disadvantage of the PRECHARGE command  
is that it requires that the command and address buses be  
available at the appropriate time to issue the command; the  
advantage of the PRECHARGE command is that it can be  
used to truncate fixed-length or full-page bursts.  
During WRITE bursts, the first valid data-in element will be  
registeredcoincidentwiththeWRITEcommand. Subsequent  
data elements will be registered on each successive  
positive clock edge. Upon completion of a fixed-length  
burst, assuming no other commands have been initiated,  
theDQswillremainHigh-Zandanyadditionalinputdatawill  
be ignored (see WRITE Burst). A full-page burst will  
continueuntilterminated. (Attheendofthepage, itwillwrap  
to column 0 and continue.)  
Fixed-length or full-page WRITE bursts can be truncated  
withtheBURSTTERMINATEcommand.Whentruncating  
a WRITE burst, the input data applied coincident with the  
BURST TERMINATE command will be ignored. The last  
data written (provided that DQM is LOW at that time) will  
be the input data applied one clock previous to the BURST  
TERMINATE command. This is shown in WRITE Burst  
Termination, where data n is the last desired data element  
of a longer burst.  
Data for any WRITE burst may be truncated with a  
subsequent WRITE command, and data for a fixed-length  
WRITE burst may be immediately followed by data for a  
WRITEcommand.ThenewWRITEcommandcanbeissued  
on any clock following the previous WRITE command, and  
the data provided coincident with the new command applies  
to the new command.  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
27  
12/01/01  
®
IS42S16400L  
ISSI  
WRITE Burst  
T0  
T1  
T2  
T3  
CLK  
COMMAND  
ADDRESS  
DQ  
WRITE  
NOP  
NOP  
NOP  
BANK,  
COL n  
DIN  
n
DIN n+1  
DON'T CARE  
WRITE to WRITE  
T0  
T1  
T2  
CLK  
COMMAND  
ADDRESS  
DQ  
WRITE  
NOP  
WRITE  
BANK,  
COL n  
BANK,  
COL b  
DIN  
n
DIN n+1  
DIN b  
DON'T CARE  
Random WRITE Cycles  
T0  
T1  
T2  
T3  
CLK  
COMMAND  
ADDRESS  
DQ  
WRITE  
WRITE  
WRITE  
WRITE  
BANK,  
COL n  
BANK,  
COL b  
BANK,  
COL m  
BANK,  
COL x  
DIN  
n
DIN  
b
DIN  
m
DIN x  
28  
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12/01/01  
®
IS42S16400L  
ISSI  
WRITE to READ  
T0  
T1  
T2  
T3  
T4  
T5  
CLK  
COMMAND  
ADDRESS  
DQ  
WRITE  
NOP  
READ  
NOP  
NOP  
NOP  
BANK,  
COL n  
BANK,  
COL b  
DIN  
n
DIN n+1  
D
OUT  
b
DOUT b+1  
DON'T CARE  
WRITE to PRECHARGE (tWR @ tCK ≥ 15ns)  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
CLK  
DQM  
tRP  
PRECHARGE  
COMMAND  
ADDRESS  
DQ  
WRITE  
NOP  
NOP  
NOP  
ACTIVE  
NOP  
BANK a,  
COL n  
BANK  
(a or all)  
BANK a,  
ROW  
tWR  
DIN n+1  
DIN n  
DON'T CARE  
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PRELIMINARY SPECIFICATION Rev. 00A  
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12/01/01  
®
IS42S16400L  
ISSI  
WRITE to PRECHARGE (tWR @ tCK < 15ns)  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
CLK  
DQM  
tRP  
PRECHARGE  
COMMAND  
ADDRESS  
DQ  
WRITE  
NOP  
NOP  
NOP  
ACTIVE  
NOP  
BANK a,  
COL n  
BANK  
(a or all)  
BANK a,  
ROW  
tWR  
DIN  
n
DIN n+1  
DON'T CARE  
WRITE Burst Termination  
T0  
T1  
T2  
CLK  
COMMAND  
ADDRESS  
DQ  
BURST  
TERMINATE  
NEXT  
WRITE  
COMMAND  
BANK,  
COL n  
(ADDRESS)  
DIN  
n
(DATA)  
DON'T CARE  
30  
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PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
PRECHARGECommand  
PRECHARGE  
The PRECHARGE command (see figure) is used to  
deactivate the open row in a particular bank or the open  
row in all banks. The bank(s) will be available for a  
subsequent row access some specified time (tRP) after  
the PRECHARGE command is issued. Input A10 deter-  
mines whether one or all banks are to be precharged, and  
in the case where only one bank is to be precharged,  
inputs BA0, BA1 select the bank. When all banks are to be  
precharged, inputs BA0, BA1 are treated as “Don’t Care.”  
Onceabankhasbeenprecharged,itisintheidlestateand  
must be activated prior to any READ or WRITE com-  
mands being issued to that bank.  
CLK  
HIGH - Z  
CKE  
CS  
RAS  
CAS  
WE  
A0-A9, A11  
ALL BANKS  
A10  
POWER-DOWN  
BANK SELECT  
Power-down occurs if CKE is registered LOW coincident  
with a NOP or COMMAND INHIBIT when no accesses are  
in progress. If power-down occurs when all banks are idle,  
this mode is referred to as precharge power-down; if  
power-down occurs when there is a row active in either  
bank, this mode is referred to as active power-down.  
Entering power-down deactivates the input and output  
buffers, excluding CKE, for maximum power savings  
while in standby. The device may not remain in the power-  
down state longer than the refresh period (64ms) since no  
refresh operations are performed in this mode.  
BANK ADDRESS  
BA0, BA1  
The power-down state is exited by registering a NOP or  
COMMAND INHIBIT and CKE HIGH at the desired clock  
edge (meeting tCKS). See figure below.  
POWER-DOWN  
CLK  
t
CKS  
≥ tCKS  
CKE  
COMMAND  
NOP  
NOP  
ACTIVE  
t
t
t
RCD  
RAS  
RC  
All banks idle  
Input buffers gated off  
Enter power-down mode  
Exit power-down mode  
DON'T CARE  
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PRELIMINARY SPECIFICATION Rev. 00A  
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®
IS42S16400L  
ISSI  
Any command or data present on the input pins at the time  
of a suspended internal clock edge is ignored; any data  
presentontheDQpinsremainsdriven;andburstcounters  
are not incremented, as long as the clock is suspended.  
(See following examples.)  
CLOCKSUSPEND  
Clock suspend mode occurs when a column access/burst  
is in progress and CKE is registered LOW. In the clock  
suspend mode, the internal clock is deactivated, “freezing”  
the synchronous logic.  
Clock suspend mode is exited by registering CKE HIGH;  
the internal clock and related operation will resume on the  
subsequent positive clock edge.  
For each positive clock edge on which CKE is sampled  
LOW, the next internal positive clock edge is suspended.  
Clock Suspend During WRITE Burst  
T0  
T1  
T2  
T3  
T4  
T5  
CLK  
CKE  
INTERNAL  
CLOCK  
COMMAND  
ADDRESS  
DQ  
NOP  
WRITE  
NOP  
NOP  
BANK a,  
COL n  
DIN  
n
DIN n+1  
DIN n+2  
DON'T CARE  
Clock Suspend During WRITE Burst  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
CLK  
CKE  
INTERNAL  
CLOCK  
COMMAND  
ADDRESS  
DQ  
READ  
NOP  
NOP  
NOP  
NOP  
NOP  
BANK a,  
COL n  
DIN  
n
D
IN n+1  
D
IN n+2  
D
IN n+3  
DON'T CARE  
32  
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PRELIMINARYSPECIFICATION Rev. 00A  
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®
IS42S16400L  
ISSI  
BURST READ/SINGLE WRITE  
Four cases where CONCURRENT AUTO PRECHARGE  
occurs are defined below.  
The burst read/single write mode is entered by programming  
the write burst mode bit (M9) in the mode register to a logic 1.  
In this mode, all WRITE commands result in the access of a  
single column location (burst of one), regardless of the  
programmed burst length. READ commands access  
columns according to the programmed burst length and  
sequence, just as in the normal mode of operation (M9 = 0).  
READ with Auto Precharge  
1. Interrupted by a READ (with or without auto precharge):  
AREADtobankmwillinterruptaREADonbankn, CAS  
latency later. The PRECHARGE to bank n will begin  
when the READ to bank m is registered.  
2.InterruptedbyaWRITE(withorwithoutautoprecharge):  
A WRITE to bank m will interrupt a READ on bank n  
when registered. DQM should be used two clocks prior  
to the WRITE command to prevent bus contention. The  
PRECHARGE to bank n will begin when the WRITE to  
bank m is registered.  
CONCURRENTAUTOPRECHARGE  
An access command (READ or WRITE) to another bank  
while an access command with auto precharge enabled is  
executing is not allowed by SDRAMs, unless the SDRAM  
supports CONCURRENT AUTO PRECHARGE. ISSI  
SDRAMs support CONCURRENT AUTO PRECHARGE.  
Fig CAP 1 - READ With Auto Precharge interrupted by a READ  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
CLK  
READ - AP  
BANK n  
READ - AP  
BANK m  
NOP  
NOP  
NOP  
NOP  
NOP  
NOP  
Idle  
COMMAND  
BANK n  
Page Active  
READ with Burst of 4  
Page Active  
Interrupt Burst, Precharge  
t
RP - BANK n  
t
RP - BANK m  
Internal States  
BANK m  
READ with Burst of 4  
Precharge  
BANK n,  
COL a  
BANK m,  
COL b  
ADDRESS  
DQ  
DOUT  
a
DOUT a+1  
DOUT  
b
DOUT b+1  
CAS Latency - 3 (BANK n)  
CAS Latency - 3 (BANK m)  
DON'T CARE  
Fig CAP 2 - READ With Auto Precharge interrupted by a WRITE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
CLK  
WRITE - AP  
BANK n  
WRITE - AP  
BANK m  
COMMAND  
NOP  
NOP  
NOP  
NOP  
NOP  
NOP  
Idle  
BANK n  
READ with Burst of 4  
Page Active  
Interrupt Burst, Precharge  
Page Active  
t
RP - BANK n  
tRP - BANK m  
Internal States  
BANK m  
WRITE with Burst of 4  
Write-Back  
BANK n,  
COL a  
BANK m,  
COL b  
ADDRESS  
DQM  
DQ  
DOUT  
a
DIN  
b
DIN b+1  
DIN b+2  
DIN b+3  
CAS Latency - 3 (BANK n)  
DON'T CARE  
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PRELIMINARY SPECIFICATION Rev. 00A  
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®
IS42S16400L  
ISSI  
WRITE with Auto Precharge  
one clock prior to the READ to bank m.  
4.InterruptedbyaWRITE(withorwithoutautoprecharge):  
WRITE to bank m will interrupt a WRITE on bank n when  
3. Interrupted by a READ (with or without auto precharge):  
AREADtobankmwillinterruptaWRITEonbanknwhen  
registered, with the data-out appearing CAS latency later.  
The PRECHARGE to bank n will begin after tWR is met,  
wheretWR beginswhentheREADtobankmisregistered.  
The last valid WRITE to bank n will be data-in registered  
A
registered. The PRECHARGE to bank n will begin after  
tWR is met, where tWR begins when the WRITE to bank  
m is registered. The last valid data WRITE to bank n will  
be data registered one clock prior to a WRITE to bank m.  
Fig CAP 3 - WRITE With Auto Precharge interrupted by a READ  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
CLK  
COMMAND  
BANK n  
WRITE - AP  
BANK n  
READ - AP  
BANK m  
NOP  
NOP  
NOP  
NOP  
NOP  
NOP  
Page Active  
WRITE with Burst of 4 Interrupt Burst, Write-Back  
WR - BANK n  
Precharge  
t
tRP - BANK n  
Internal States  
t
RP - BANK m  
BANK m  
Page Active  
READ with Burst of 4  
Precharge  
BANK n,  
COL a  
BANK m,  
COL b  
ADDRESS  
DQ  
DIN  
a
DIN a+1  
DOUT  
b
DOUT b+1  
CAS Latency - 3 (BANK m)  
DON'T CARE  
Fig CAP 4 - WRITE With Auto Precharge interrupted by a WRITE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
CLK  
COMMAND  
BANK n  
WRITE - AP  
BANK n  
WRITE - AP  
BANK m  
NOP  
NOP  
NOP  
NOP  
NOP  
NOP  
Page Active  
WRITE with Burst of 4  
Interrupt Burst, Write-Back  
WR - BANK n  
Precharge  
t
t
RP - BANK n  
Internal States  
t
RP - BANK m  
BANK m  
Page Active  
WRITE with Burst of 4  
Write-Back  
BANK n,  
COL a  
BANK m,  
COL b  
ADDRESS  
DQ  
DIN  
a
DIN a+1  
DIN a+2  
D
IN  
b
DIN b+1  
DIN b+2  
DIN b+3  
DON'T CARE  
34  
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PRELIMINARYSPECIFICATION Rev. 00A  
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®
IS42S16400L  
ISSI  
INITIALIZE AND LOAD MODE REGISTER  
T0  
T1  
Tn+1  
To+1  
t
CL  
Tp+1  
Tp+2  
Tp+3  
t
CK  
t
CH  
CLK  
CKE  
t
CKS t  
CKH  
t
CMH  
t
CMS  
t
CMH  
t
CMS  
tCMH tCMS  
AUTO  
REFRESH  
AUTO  
Load MODE  
REGISTER  
COMMAND  
NOP  
PRECHARGE  
NOP  
NOP  
NOP  
ACTIVE  
REFRESH  
DQM/  
DQML, DQMH  
t
t
AS  
tAH  
A0-A9, A11  
A10  
ROW  
ROW  
BANK  
CODE  
AS  
tAH  
ALL BANKS  
CODE  
SINGLE BANK  
ALL BANKS  
BA0, BA1  
DQ  
T
t
RP  
t
RFC  
t
RFC  
tMRD  
Power-up: VCC  
and CLK stable all banks  
Precharge AUTO REFRESH  
AUTO REFRESH  
Program MODE REGISTER(2, 3, 4)  
DON'T CARE  
T = 100µs Min.  
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®
IS42S16400L  
ISSI  
POWER-DOWN MODE CYCLE  
T0  
T1  
T2  
Tn+1  
Tn+2  
t
CK  
t
CL  
t
CH  
CLK  
t
CKS  
t
CKH  
t
CKS  
t
CKS  
CKE  
t
CMS  
t
CMH  
COMMAND  
PRECHARGE  
NOP  
NOP  
NOP  
ACTIVE  
DQM/  
DQML, DQMH  
A0-A9, A11  
A10  
ROW  
ROW  
ALL BANKS  
SINGLE BANK  
t
AS  
t
AH  
BA0, BA1  
DQ  
BANK  
BANK  
High-Z  
Two clock cycles  
Input buffers gated  
All banks idle  
off while in  
Precharge all  
active banks  
All banks idle, enter  
power-down mode  
power-down mode  
DON'T CARE  
Exit power-down mode  
CAS latency = 2, 3  
36  
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PRELIMINARYSPECIFICATION Rev. 00A  
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®
IS42S16400L  
ISSI  
CLOCK SUSPEND MODE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
T9  
t
CK  
t
CL  
t
CH  
CLK  
CKE  
t
CKS  
t
CKH  
t
CKS  
t
CKH  
t
CMS  
tCMH  
COMMAND  
READ  
NOP  
NOP  
NOP  
NOP  
NOP  
WRITE  
NOP  
t
CMS tCMH  
DQM/  
DQML, DQMH  
t
AS  
tAH  
COLUMN n(2)  
A0-A9, A11  
A10  
COLUMN m(2)  
t
AS  
t
AH  
t
AS  
t
AH  
BA0, BA1  
BANK  
BANK  
t
DS  
tDH  
t
AC  
t
AC  
t
HZ  
DQ  
DOUT  
m
DOUT m+1  
DOUT e  
DOUT e+1  
t
LZ  
tOH  
DON'T CARE  
UNDEFINED  
CAS latency = 2, burst length = 2  
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®
IS42S16400L  
ISSI  
AUTO-REFRESHCYCLE  
T0  
T1  
T2  
Tn+1  
To+1  
t
CK  
t
CL  
t
CH  
CLK  
t
CKS CKH  
t
CKE  
t
CMS  
t
CMH  
Auto  
Refresh  
Auto  
COMMAND  
PRECHARGE  
NOP  
NOP  
NOP  
ACTIVE  
Refresh  
DQM/  
DQML, DQMH  
A0-A9, A11  
A10  
ROW  
ROW  
BANK  
ALL BANKS  
SINGLE BANK  
BANK(s)  
BA0, BA1  
DQ  
t
AS  
t
AH  
High-Z  
t
RP  
t
RFC  
t
RFC  
DON'T CARE  
CAS latency = 2, 3  
38  
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PRELIMINARYSPECIFICATION Rev. 00A  
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®
IS42S16400L  
ISSI  
SELF-REFRESHCYCLE  
T0  
T1  
T2  
Tn+1  
To+1  
To+2  
t
CK  
t
CH  
t
CL  
CLK  
CKE  
t
CKS  
t
CKH  
t
CKS  
≥ tRAS  
t
CKS  
t
CMS  
t
CMH  
Auto  
Auto  
COMMAND  
PRECHARGE  
NOP  
NOP  
NOP  
Refresh  
Refresh  
DQM/  
DQML, DQMH  
A0-A9, A11  
A10  
ALL BANKS  
SINGLE BANK  
t
AS  
t
AH  
BA0, BA1  
DQ  
BANK  
High-Z  
t
XSR  
t
RP  
Precharge all  
active banks  
Enter self  
refresh mode  
CLK stable prior to exiting  
self refresh mode  
Exit self refresh mode  
(Restart refresh time base)  
DON'T CARE  
CAS latency = 2, 3  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
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®
IS42S16400L  
ISSI  
READ WITHOUT AUTO PRECHARGE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS tCMH  
COMMAND  
ACTIVE  
NOP  
READ  
NOP  
NOP  
NOP  
PRECHARGE  
NOP  
ACTIVE  
t
CMS  
t
CMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
A0-A9, A11  
A10  
ROW  
ROW  
ROW  
BANK  
AS  
t
AH  
ALL BANKS  
ROW  
AS  
t
AH  
DISABLE AUTO PRECHARGE  
SINGLE BANK  
BANK  
BA0, BA1  
DQ  
BANK  
BANK  
t
AC  
t
AC  
t
AC  
t
AC  
tHZ  
DOUT  
m
D
OUT m+1  
DOUT m+2  
D
OUT m+3  
t
LZ  
t
OH  
t
OH  
t
OH  
tOH  
tRCD  
tRAS  
t
RC  
CAS Latency  
DON'T CARE  
UNDEFINED  
t
RP  
40  
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®
IS42S16400L  
ISSI  
READ WITH AUTO PRECHARGE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS tCMH  
COMMAND  
ACTIVE  
NOP  
READ  
NOP  
NOP  
NOP  
NOP  
NOP  
ACTIVE  
t
CMS  
t
CMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
A0-A9, A11  
A10  
ROW  
ROW  
ROW  
BANK  
AS  
t
AH  
ENABLE AUTO PRECHARGE  
ROW  
AS  
t
AH  
BA0, BA1  
DQ  
BANK  
BANK  
t
AC  
t
AC  
t
AC  
t
AC  
tHZ  
DOUT  
m
D
OUT m+1  
D
OUT m+2  
D
OUT m+3  
t
LZ  
t
OH  
t
OH  
t
OH  
tOH  
t
t
t
RCD  
RAS  
RC  
CAS Latency  
DON'T CARE  
UNDEFINED  
t
RP  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
41  
12/01/01  
®
IS42S16400L  
ISSI  
SINGLE READ WITHOUT AUTO PRECHARGE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS tCMH  
COMMAND  
ACTIVE  
NOP  
READ  
NOP  
NOP  
PRECHARGE  
NOP  
ACTIVE  
NOP  
tCMS  
t
CMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
A0-A9, A11  
A10  
ROW  
ROW  
ROW  
BANK  
AS  
t
AH  
ALL BANKS  
ROW  
SINGLE BANK  
BANK  
AS  
t
AH  
DISABLE AUTO PRECHARGE  
BA0, BA1  
DQ  
BANK  
BANK  
t
OH  
t
AC  
D
OUT m  
t
LZ  
t
HZ  
DON'T CARE  
UNDEFINED  
t
t
t
RCD  
RAS  
RC  
CAS Latency  
t
RP  
42  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
SINGLE READ WITH AUTO PRECHARGE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS  
tCMH  
COMMAND  
ACTIVE  
NOP  
NOP  
NOP  
READ  
NOP  
NOP  
ACTIVE  
NOP  
tCMS  
t
CMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
A0-A9, A11  
A10  
ROW  
ROW  
ROW  
BANK  
AS  
t
AH  
ENABLE AUTO PRECHARGE  
ROW  
AS  
t
AH  
BA0, BA1  
BANK  
BANK  
t
OH  
t
AC  
DOUT m  
DQ  
t
HZ  
DON'T CARE  
UNDEFINED  
t
t
t
RCD  
RAS  
RC  
CAS Latency  
t
RP  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
43  
12/01/01  
®
IS42S16400L  
ISSI  
ALTERNATINGBANKREADACCESSES  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS  
tCMH  
COMMAND  
ACTIVE  
NOP  
READ  
NOP  
ACTIVE  
NOP  
READ  
NOP  
ACTIVE  
t
CMS tCMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
ROW  
ROW  
COLUMN b(2)  
ROW  
ROW  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ENABLE AUTO PRECHARGE  
ENABLE AUTO PRECHARGE  
ROW  
AS  
tAH  
BANK 0  
BANK 3  
BANK 3  
BANK 0  
BA0, BA1  
BANK 0  
tLZ  
tOH  
tOH  
tOH  
tOH  
tOH  
DQ  
DOUT  
m
D
OUT m+  
1
DOUT m+  
2
DOUT m+  
3
DOUT b  
t
AC  
t
AC  
t
AC  
t
AC  
t
AC  
t
AC  
t
t
t
t
RCD - BANK 0  
RRD  
CAS Latency - BANK 0  
t
RP - BANK 0  
tRCD - BANK 0  
t
RCD - BANK 3  
CAS Latency - BANK 3  
RAS - BANK 0  
RC - BANK 0  
DON'T CARE  
44  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
READ - FULL-PAGE BURST  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
Tn+1  
Tn+2  
Tn+3  
Tn+4  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS  
tCMH  
COMMAND  
ACTIVE  
NOP  
READ  
CMS CMH  
NOP  
NOP  
NOP  
NOP  
NOP  
BURST TERM  
NOP  
NOP  
t
t
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ROW  
AS  
t
AH  
BA0, BA1  
BANK  
BANK  
t
AC  
t
AC  
t
AC  
t
AC  
t
AC  
t
AC  
tHZ  
D
OUT  
m
D
OUT m+  
1
D
OUT m+  
2
D
OUT m-  
1
D
OUT  
m
D
OUT m+1  
DQ  
t
LZ  
t
OH  
t
OH  
t
OH  
t
OH  
t
OH  
tOH  
t
RCD  
CAS Latency  
each row (x4) has  
1,024 locations  
DON'T CARE  
UNDEFINED  
Full page Full-page burst not self-terminating.  
completion Use BURST TERMINATE command.  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
45  
12/01/01  
®
IS42S16400L  
ISSI  
READ - DQM OPERATION  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS tCMH  
COMMAND  
ACTIVE  
NOP  
READ  
NOP  
NOP  
NOP  
NOP  
NOP  
NOP  
t
CMS  
t
CMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ENABLE AUTO PRECHARGE  
ROW  
DISABLE AUTO PRECHARGE  
AS  
t
AH  
BA0, BA1  
BANK  
BANK  
t
OH  
t
OH  
tOH  
t
AC  
tAC  
D
OUT  
m
D
OUT m+  
2
D
OUT m+  
3
DQ  
t
LZ  
tLZ  
t
HZ  
t
AC  
t
HZ  
DON'T CARE  
UNDEFINED  
t
RCD  
CAS Latency  
46  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
WRITE - WITHOUT AUTO PRECHARGE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS tCMH  
COMMAND  
ACTIVE  
NOP  
WRITE  
NOP  
NOP  
NOP  
PRECHARGE  
NOP  
ACTIVE  
t
CMS tCMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(3)  
ROW  
ROW  
BANK  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ALL BANKS  
ROW  
AS  
t
AH  
SINGLE BANK  
BANK  
DISABLE AUTO PRECHARGE  
BANK  
BA0, BA1  
BANK  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
tDH  
t
DS  
tDH  
DQ  
DIN  
m
D
IN m+  
1
DIN m+  
2
DIN m+3  
t
t
t
RCD  
RAS  
RC  
t
WR(2)  
t
RP  
DON'T CARE  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
47  
12/01/01  
®
IS42S16400L  
ISSI  
WRITE - WITH AUTO PRECHARGE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
T9  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS  
tCMH  
COMMAND  
ACTIVE  
NOP  
WRITE  
NOP  
NOP  
NOP  
NOP  
NOP  
NOP  
ACTIVE  
t
CMS tCMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
ROW  
ROW  
BANK  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ENABLE AUTO PRECHARGE  
ROW  
AS  
t
AH  
BA0, BA1  
BANK  
BANK  
tDS  
t
DH  
t
DS  
t
DH  
t
DS  
tDH  
t
DS  
tDH  
DQ  
DIN  
m
DIN m+  
1
DIN m+  
2
DIN m+3  
t
t
t
RCD  
RAS  
RC  
t
WR  
tRP  
DON'T CARE  
48  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
SINGLE WRITE - WITHOUT AUTO PRECHARGE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS  
tCMH  
NOP(4)  
NOP(4)  
PRECHARGE  
NOP  
ACTIVE  
NOP  
COMMAND  
ACTIVE  
NOP  
WRITE  
t
CMS tCMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(3)  
ROW  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ALL BANKS  
ROW  
ROW  
SINGLE BANK  
AS  
t
AH  
DISABLE AUTO PRECHARGE  
BANK  
BA0, BA1  
BANK  
BANK  
BANK  
t
DS  
t
DH  
DQ  
DIN  
m
t
t
t
RCD  
RAS  
RC  
t
WR(3)  
tRP  
DON'T CARE  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
49  
12/01/01  
®
IS42S16400L  
ISSI  
SINGLE WRITE - WITH AUTO PRECHARGE  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
T9  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS tCMH  
NOP(3)  
NOP(3)  
NOP(3)  
WRITE  
NOP  
NOP  
NOP  
ACTIVE  
NOP  
COMMAND  
ACTIVE  
t
CMS tCMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
ROW  
ROW  
BANK  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ENABLE AUTO PRECHARGE  
ROW  
AS  
t
AH  
BA0, BA1  
BANK  
BANK  
t
DS  
t
DH  
DQ  
DIN  
m
t
t
t
RCD  
RAS  
RC  
t
WR  
tRP  
DON'T CARE  
50  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
ALTERNATING BANK WRITE ACCESS  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
T8  
T9  
t
CK  
t
CL  
tCH  
CLK  
CKE  
t
CKS tCKH  
t
CMS  
tCMH  
COMMAND  
ACTIVE  
NOP  
WRITE  
NOP  
ACTIVE  
NOP  
WRITE  
NOP  
NOP  
ACTIVE  
t
CMS tCMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
tAH  
COLUMN m(2)  
ROW  
ROW  
COLUMN b(2)  
ROW  
ROW  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ENABLE AUTO PRECHARGE  
ENABLE AUTO PRECHARGE  
ROW  
AS  
tAH  
BANK 0  
BANK 1  
BANK 1  
BANK 0  
BA0, BA1  
BANK 0  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
tDH  
t
DS  
tDH  
DQ  
DIN  
m
D
IN m+  
1
DIN m+  
2
DIN m+  
3
DIN  
b
D
IN b+  
1
DIN b+  
2
DIN b+3  
t
t
t
t
RCD - BANK 0  
RRD  
t
WR - BANK 0  
t
RP - BANK 0  
t
RCD - BANK 0  
t
RCD - BANK 1  
tWR - BANK 1  
RAS - BANK 0  
RC - BANK 0  
DON'T CARE  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
51  
12/01/01  
®
IS42S16400L  
ISSI  
WRITE - FULL PAGE BURST  
T0  
T1  
T2  
T3  
T4  
T5  
Tn+1  
Tn+2  
t
CK  
t
CL  
t
CH  
CLK  
CKE  
t
CKS CKH  
t
t
CMS  
t
CMH  
COMMAND  
ACTIVE  
NOP  
WRITE  
NOP  
NOP  
NOP  
NOP  
BURST TERM  
NOP  
t
CMS  
t
CMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
t
AH  
COLUMN m(2)  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ROW  
AS  
t
AH  
BA0, BA1  
BANK  
BANK  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
t
DH  
DIN  
m
DIN m+  
1
DIN m+  
2
DIN m+  
3
DIN m-1  
DQ  
t
RCD  
Full page completed  
DON'T CARE  
52  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  
®
IS42S16400L  
ISSI  
WRITE - DQM OPERATIOON  
T0  
T1  
T2  
T3  
T4  
T5  
T6  
T7  
t
CK  
t
CL  
t
CH  
CLK  
CKE  
t
CKS CKH  
t
t
CMS  
t
CMH  
COMMAND  
ACTIVE  
NOP  
WRITE  
NOP  
NOP  
NOP  
NOP  
NOP  
t
CMS  
t
CMH  
DQM/  
DQML, DQMH  
t
t
t
AS  
t
AH  
COLUMN m(2)  
A0-A9, A11  
A10  
ROW  
AS  
t
AH  
ENABLE AUTO PRECHARGE  
ROW  
DISABLE AUTO PRECHARGE  
AS  
t
AH  
BA0, BA1  
BANK  
BANK  
t
DS  
t
DH  
t
DS  
t
DH  
t
DS  
t
DH  
DIN  
m
D
IN m+  
2
DIN m+3  
DQ  
t
RCD  
DON'T CARE  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARY SPECIFICATION Rev. 00A  
53  
12/01/01  
®
IS42S16400L  
ISSI  
ORDERING INFORMATION  
Commercial Range: 0°C to 70°C  
Frequency  
166 MHz  
133 MHz  
100 MHz  
Speed (ns) Order Part No.  
Package  
6
7
IS42S16400L-6T 400-mil TSOP II  
IS42S16400L-7T 400-mil TSOP II  
IS42S16400L-10T 400-mil TSOP II  
10  
Industrial Range: -40°C to 85°C  
Frequency  
133 MHz  
100 MHz  
Speed (ns) Order Part No.  
Package  
7
IS42S16400L-7TI 400-mil TSOP II  
IS42S16400L-10TI 400-mil TSOP II  
10  
®
ISSI  
IntegratedSiliconSolution,Inc.  
2231 Lawson Lane  
Santa Clara, CA 95054  
Tel: 1-800-379-4774  
Fax: (408) 588-0806  
E-mail: sales@issi.com  
www.issi.com  
54  
Integrated Silicon Solution, Inc. — 1-800-379-4774  
PRELIMINARYSPECIFICATION Rev. 00A  
12/01/01  

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