Samsung M393T2950GZ3-CD5 用户手册
Rev. 1.0 July 2008
DDR2 SDRAM
RDIMM
22 of 26
Parameter
Symbol
DDR2-533
DDR2-400
Units
Notes
min
max
min
max
Four Activate Window for 1KB page size products
tFAW
37.5
x
37.5
x
ns
Four Activate Window for 2KB page size products
tFAW
50
x
50
x
ns
CAS to CAS command delay
tCCD
2
x
2
x
tCK
Write recovery time
tWR
15
x
15
x
ns
Auto precharge write recovery + precharge time
tDAL
WR+tRP
x
WR+tRP
x
tCK
14
Internal write to read command delay
tWTR
7.5
x
10
x
ns
24
Internal read to precharge command delay
tRTP
7.5
x
7.5
x
ns
3
Exit self refresh to a non-read command
tXSNR
tRFC + 10
x
tRFC + 10
x
ns
Exit self refresh to a read command
tXSRD
200
x
200
x
tCK
Exit precharge power down to any non-read command
tXP
2
x
2
x
tCK
Exit active power down to read command
tXARD
2
x
2
x
tCK
1
Exit active power down to read command
(slow exit, lower power)
(slow exit, lower power)
tXARDS
6 - AL
x
6 - AL
x
tCK
1,2
CKE minimum pulse width (HIGH and LOW pulse width)
tCKE
3
x
3
x
tCK
27
ODT turn-on delay
tAOND
2
2
2
2
tCK
16
ODT turn-on
tAON
tAC(min)
tAC(max)+1
tAC(min)
tAC(max)+1
ns
16
ODT turn-on (Power-Down mode)
tAONPD
tAC(min)+2
2tCK+
tAC(max)+1
tAC(min)+2
2tCK+
tAC(max)+1
ns
ODT turn-off delay
tAOFD
2.5
2.5
2.5
2.5
tCK
17,44
ODT turn-off
tAOF
tAC(min)
tAC(max)
+ 0.6
tAC(min)
tAC(max)
+ 0.6
ns
17,44
ODT turn-off (Power-Down mode)
tAOFPD
tAC(min)+2
2.5tCK+
tAC(max)+1
tAC(min)+2
2.5tCK+
tAC(max)+1
ns
ODT to power down entry latency
tANPD
3
x
3
x
tCK
ODT power down exit latency
tAXPD
8
x
8
x
tCK
OCD drive mode output delay
tOIT
0
12
0
12
ns
32
Minimum time clocks remains ON after CKE asynchronously
drops LOW
drops LOW
tDelay
tIS+tCK+tIH
x
tIS+tCK+tIH
x
ns
15