IS42S16100E, IC42S16100E
Bank Active Command Interval
thatbankwithintheACTtoPREcommandperiod(tr a s max).
Also note that a precharge command cannot be executed
for an active bank before tr a s (min) has elapsed.
When the selected bank is precharged, the period trp
has elapsed and the bank has entered the idle state,
the bank can be activated by executing the active
command. If the other bank is in the idle state at that
time, the active command can be executed for that bank
after the period tr r d has elapsed. At that point both
banks will be in the active state. When a bank active
command has been executed, a precharge command
must be executed for
After a bank active command has been executed and
the trcd period has elapsed, read write (including auto-
precharge) commands can be executed for that bank.
CLK
tRRD
COMMAND
ACT 0
ACT 1
BANK ACTIVE (BANK 0)
BANK ACTIVE (BANK 1)
CLK
COMMAND
tRCD
ACT 0
READ 0
BANK ACTIVE (BANK 0)
BANK ACTIVE (BANK 0)
CAS latency = 3
Clock Suspend
When the CKE pin is dropped from HIGH to LOW during
a read or write cycle, the IS42S16100E/IC42S16100E
enters clock suspend mode on the next CLK rising edge.
This command reduces the device power dissipation by
stopping the device internal clock. Clock suspend mode
continues as long as the CKE pin remains low. In this
state, all inputs other than CKE pin are invalid and no
othercommandscanbeexecuted.Also,thedeviceinternal
states are maintained. When the CKE pin goes from LOW
to HIGH clock suspend mode is terminated on the next
CLK rising edge and device operation resumes.
The next command cannot be executed until the recovery
period (tc k a ) has elapsed.
Sincethiscommanddiffersfromtheself-refreshcommand
described previously in that the refresh operation is not
performed automatically internally, the refresh operation
must be performed within the refresh period (tref). Thus
the maximum time that clock suspend mode can be held
is just under the refresh cycle time.
CLK
CKE
COMMAND
DQ
READ 0
D
OUT
0
DOUT
1
DOUT
2
DOUT 3
READ (BANK 0)
CLOCK SUSPEND
CAS latency = 2, burstlength = 4
36
Integrated Silicon Solution, Inc. — www.issi.com
Rev. C
01/22/08
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
