Integrated Silicon Solution, Inc. - www.issi.com 19
Rev. A
10/22/09
IS42SM83200D / IS42SM16160D / IS42SM32800D
IS42RM83200D / IS42RM16160D / IS42RM32800D
OPERATING FREQUENCY / LATENCY RELATIONSHIPS
SYMBOL PARAMETER -7 -75 -10 UNITS
— Clock Cycle Time 7 7.5 10 ns
— Operating Frequency 143 133 100 MHz
t
c a c
CAS Latency
3 3 3 cycle
tr c d Active Command To Read/Write
Command Delay Time
3 3 3 cycle
t
r a c
RAS Latency (tr c d + tc a c ) CAS Latency = 3
6 6 6 cycle
t
r c Command Period (REF to REF / ACT to
ACT)
10 9 9 cycle
t
r a s Command Period (ACT to PRE) 7 6 6 cycle
tr p Command Period (PRE to ACT) 3 3 3 cycle
t
r r d Command Period (ACT[0] to ACT [1]) 2 2 2 cycle
tc c d Column Command Delay Time
(READ, READA, WRIT, WRITA)
1 1 1 cycle
t
d p l Input Data To Precharge Command Delay
Time
2 2 2 cycle
t
d a l Input Data To Active/Refresh Command
Delay Time
(During Auto-Precharge)
5 5 5 cycle
tr b d
Burst Stop Command To Output in HIGH-Z
Delay Time
(Write)
CAS Latency = 3
3 3 3 cycle
t
w b d Burst Stop Command To Input in Invalid
Delay Time
(Write)
0 0 0 cycle
tr q l
Precharge Command To Output in HIGH-Z
Delay Time
(Read)
CAS Latency = 3
3 3 3 cycle
t
w d l Precharge Command To Input in Invalid
Delay Time
(Write)
0 0 0 cycle
t
p q l
Last Output To Auto-Precharge Start
Time (Read)
CAS Latency = 3
-2 -2 -2 cycle
t
q m d DQM To Output Delay Time (Read) 2 2 2 cycle
t
d m d DQM To Input Delay Time (Write) 0 0 0 cycle
tm r d Mode Register Set To Command Delay
Time
2 2 2 cycle
