28
www.issi.com - DRAM@issi.com
Rev. A | Apr. 2012
IS42/45SM/RM/VM16800G
Table12: AC Characteristic (AC operation conditions unless otherwise noted)
Parameter Sym
-6 -75
Unit Note
Min Max Min Max
CLK Cycle Time
CL = 3 tCK3 6.0
1000
7.5
1000
ns
1
CL = 2 tCK2 10 10
Access time from CLK (pos. edge)
CL = 3 tAC3 5.5 6
2
CL = 2 tAC2 8 8
CLK High-Level Width tCH 2.5 2.5 3
CLK Low-Level Width tCL 2.5 2.5 3
CKE Setup Time tCKS 1.5 2.0
CKE Hold Time tCKH 1.0 1.0
/CS, /RAS, /CAS, /WE, DQM Setup Time tCMS 1.5 2.0
/CS, /RAS, /CAS, /WE, DQM Hold Time tCMH 1.0 1.0
Address Setup Time tAS 1.5 2.0
Address Hold Time tAH 1.0 1.0
Data-In Setup Time tDS 1.5 2.0
Data-In Hold Time tDH 1.0 1.0
Data-Out High-Impedance Time
from CLK (pos.edge)
CL = 3 tHZ3 5.5 6
4
CL = 2 tHZ2 8 8
Data-Out Low-Impedance Time tLZ 1.0 1.0
Data-Out Hold Time (load) tOH 2.5 2.5
Data-Out Hold Time (no load) tOHN
1.8 1.8
ACTIVE to PRECHARGE command tRAS 42 100K 45 100K
PRECHARGE command period tRP 18 19
ACTIVE bank a to ACTIVE bank a command tRC 60 67.5 5
ACTIVE bank a to ACTIVE bank b command tRRD 12 15
ACTIVE to READ or WRITE delay tRCD 18 19
READ/WRITE command to READ/WRITE
command
tCCD 1 1
CLK
6
WRITE command to input data delay tDWD 0 0 6
Data-in to PRECHARGE command tDPL 12 15
ns
7
Data-in to ACTIVE command tDAL 30 37.5 7
DQM to data high-impedance during READs tDQZ 2 2
CLK
6
DQM to data mask during WRITEs tDQM 0 0 6
LOAD MODE REGISTER command to ACTIVE
or REFRESH command
tMRD 2 2 8
Data-out to high-impedance from
PRECHARGE command
CL = 3 tROH3 3 3
6
CL = 2 tROH2 2 2
Last data-in to burst STOP command tBDL 1 1 6
Last data-in to new READ/WRITE command tCDL 1 1 6
CKE to clock disable or power-down entry
mode
tCKED 1 1
CLK
9
CKE to clock enable or power-down exit
setup mode
tPED 1 1 9
Refresh period (4,096 rows)
tREF 64 64 ms
AUTO REFRESH period tRFC 80 80
ns
5
Exit SELF REFRESH to ACTIVE command tXSR 80 80 5
Transition time tT 0.5 1.2 0.5 1.2
