is45s16400e Integrated Silicon Solution, Inc., is45s16400e Datasheet - Page 21

• Manufacturer Part Number: is45s16400e
• Description: 1 Meg Bits X 16 Bits X 4 Banks 64-mbit Synchronous Dynamic Ram
• Manufacturer: Integrated Silicon Solution, Inc.

IS45S16400E
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 t
of the row precharge time is hidden during the access of the
last data element(s).
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
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
CAS Latency
Integrated Silicon Solution, Inc. — www.issi.com
Rev. A
02/04/08
COMMAND
COMMAND
CLK
CLK
DQ
DQ
RP
is met. Note that part
READ
READ
T0
T0
CAS Latency - 2
NOP
NOP
CAS Latency - 3
T1
T1
t
LZ
t
AC
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
BURST TERMINATE 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 the READ Burst Termination
diagram for each possible CAS latency; data element n +
3 is the last desired data element of a longer burst.
NOP
NOP
T2
T2
D
OUT
t
t
OH
LZ
t
AC
NOP
T3
T3
D
DON'T CARE
UNDEFINED
OUT
t
OH
T4
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