Datasheet

Rev. 1.0 July 2008
DDR2 SDRAM
RDIMM
20 of 26
Parameter Symbol
DDR2-800 DDR2-667
Units
Notes
min max min max
Four Activate Window for 1KB page size products tFAW 35 x 37.5 x ns 32
Four Activate Window for 2KB page size products tFAW 45 x 50 x ns 32
CAS to CAS command delay tCCD 2 x 2 x nCK
Write recovery time tWR 15 x 15 x ns 32
Auto precharge write recovery + precharge time tDAL WR + tnRP x WR + tnRP x nCK 33
Internal write to read command delay tWTR 7.5 x7.5x ns 24,32
Internal read to precharge command delay tRTP 7.5 x7.5x ns 3,32
Exit self refresh to a non-read command tXSNR tRFC + 10 xtRFC + 10x ns 32
Exit self refresh to a read command tXSRD 200 x200x nCK
Exit precharge power down to any command tXP 2 x 2 x nCK
Exit active power down to read command tXARD 2 x 2 x nCK 1
Exit active power down to read command
(slow exit, lower power)
tXARDS 8 - AL x 7 - AL x nCK 1,2
CKE minimum pulse width (HIGH and LOW pulse width) tCKE
3 x 3 x nCK 27
ODT turn-on delay tAOND 2 2 2 2
nCK 16
ODT turn-on tAON tAC(min) tAC(max)+0.7 tAC(min) tAC(max)+0.7 ns 6,16,40
ODT turn-on (Power-Down mode) tAONPD tAC(min)+2
2*tCK(avg)
+tAC(max)+1
tAC(min)+2
2*tCK(avg)
+tAC(max)+1
ns
ODT turn-off delay tAOFD 2.5 2.5 2.5 2.5
nCK 17,45
ODT turn-off tAOF tAC(min) tAC(max)+0.6 tAC(min) tAC(max)+0.6 ns 17,43,45
ODT turn-off (Power-Down mode) tAOFPD tAC(min)+2
2.5*tCK(avg)+
tAC(max)+1
tAC(min)+2
2.5*tCK(avg)+
tAC(max)+1
ns
ODT to power down entry latency tANPD 3
x3x nCK
ODT power down exit latency tAXPD 8
x8x nCK
OCD drive mode output delay tOIT 0 12 0 12 ns 32
Minimum time clocks remains ON after CKE asynchronously
drops LOW
tDelay
tIS+tCK(avg)
+tIH
x
tIS+tCK(avg)
+tIH
xns15