®
IS42S32400B
ISSI
OPERATING FREQUENCY / LATENCY RELATIONSHIPS
SYMBOL PARAMETER
UNITS
—
—
Clock Cycle Time
6
7
8
10
ns
Operating Frequency
166
143
125
100
MHz
tCAC
tRCD
tRAC
CAS Latency
3
3
3
3
2/3
3
2/3
2
cycle
cycle
cycle
Active Command To Read/Write Command Delay Time
RAS Latency (tRCD + tCAC)
CAS Latency = 3
CAS Latency = 2
6
—
6
—
6
5
5
4
tRC
Command Period (REF to REF / ACT to ACT)
Command Period (ACT to PRE)
10
7
10
7
8
6
3
2
1
7
5
2
2
1
cycle
cycle
cycle
cycle
cycle
tRAS
tRP
Command Period (PRE to ACT)
3
3
tRRD
tCCD
Command Period (ACT[0] to ACT [1])
2
2
Column Command Delay Time
(READ, READA, WRIT, WRITA)
1
1
tDPL
Input Data To Precharge Command Delay Time
2
5
2
5
2
4
2
4
cycle
cycle
tDAL
Input Data To Active/Refresh Command Delay Time
(During Auto-Precharge)
tRBD
tWBD
tRQL
tWDL
tPQL
Burst Stop Command To Output in HIGH-Z Delay Time CAS Latency = 3
3
—
3
—
3
2
3
2
cycle
cycle
cycle
cycle
cycle
(Read)
CAS Latency = 2
Burst Stop Command To Input in Invalid Delay Time
(Write)
0
0
0
0
PrechargeCommandToOutputinHIGH-ZDelayTime
(Read)
CAS Latency = 3
CAS Latency = 2
3
—
3
—
3
2
3
2
Precharge Command To Input in Invalid Delay Time
(Write)
0
0
0
0
LastOutputToAuto-PrechargeStartTime(Read)
CAS Latency = 3
CAS Latency = 2
-2
—
–2
—
-2
-1
-2
-1
tQMD
tDMD
tMRD
DQM To Output Delay Time (Read)
DQM To Input Delay Time (Write)
2
0
2
2
0
2
2
0
2
2
0
2
cycle
cycle
cycle
Mode Register Set To Command Delay Time
Integrated Silicon Solution, Inc. — www.issi.com — 1-800-379-4774
17
PRELIMINARYINFORMATION Rev. 00G
06/15/06
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
