Discontinued (12/98 - last order; 9/99 last ship)
IBM0316409C IBM0316809C IBM0316169C
IBM03164B9C
16Mb Synchronous DRAM-Die Revision D
Termination of a Burst Write Operation (Burst Length =X, CAS Latency = 1, 2, 3)
T0
T1
T2
T3
T4
T5
T6
T7
T8
CLK
Burst
Stop
NOP
WRITE A
NOP
NOP
NOP
NOP
NOP
NOP
COMMAND
CAS latency = 1,2,3
don’t care
DIN A
0
DIN A
DIN A
2
1
DQs
Input data for the Write is masked.
Auto-Precharge Operation
Before a new row in an active bank can be opened, the active bank must be precharged using either the Pre-
charge Command or the auto-precharge function. When a Read or a Write Command is given to the SDRAM,
the CAS timing accepts one extra address, column address A10, to allow the active bank to automatically
begin precharge at the earliest possible moment during the burst read or write cycle. If A10 is low when the
Read or Write Command is issued, then normal Read or Write burst operation is executed and the bank
remains active at the completion of the burst sequence. If A10 is high when the Read or Write Command is
issued, then the auto-precharge function is engaged. During auto-precharge, a Read Command will execute
as normal with the exception that the active bank will begin to precharge immediately and may finish before
all burst read cycles have been completed. This feature allows the precharge operation to be partially or com-
pletely hidden during the burst read cycles (dependent upon burst length) thus improving system perfor-
mance for random data access. Auto-precharge can also be implemented during Write commands.
A Read or Write Command without auto-precharge can be terminated in the midst of a burst operation. How-
ever, a Read or Write Command with auto-precharge can not be interrupted by a command to the same
bank. Therefore use of a Read, Write, Precharge, or Burst Stop Command to the same bank is prohibited
during a read or write cycle with auto-precharge until the entire burst operation is completed.
If A10 is high when a Read Command is issued, the Read with auto-precharge function is initiated. Once the
precharge operation has started the bank cannot be reactivated until an asynchronous delay time equal to tRP
+ tDPL, expressed in nanoseconds rather than clocks, has been satisfied. It should be noted that the device will
not respond to the Auto-Precharge Command if the device is programmed for full page burst read or write
cycles.
©IBM Corporation. All rights reserved.
Use is further subject to the provisions at the end of this document.
08J3348.E35853
5/98
Page 21 of 120
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