Electrical Specifications
9.6.6
SDRAM DDR2 Interface AC Timing
9.6.6.1
SDRAM DDR2 400 MHz Interface AC Timing Table
Table 35: SDRAM DDR2 400 MHz Interface AC Timing Table
400 MHz @ 1.8V
Description
Symbol
Min
Max
Units
MHz
Notes
Clock frequency
fCK
tDOVB
tDOVA
tDIPW
tDQSH
tDQSL
tDSS
tDSH
tDQSS
tWPRE
tWPST
tCH
400.0
-
-
DQ and DM valid output time before DQS transition
DQ and DM valid output time after DQS transition
DQ and DM output pulse w idth
0.38
0.38
0.35
0.35
0.35
0.34
0.34
-0.11
0.35
0.41
0.48
0.48
-0.40
0.60
0.67
-
ns
-
ns
-
-
tCK(avg)
tCK(avg)
tCK(avg)
tCK(avg)
tCK(avg)
tCK(avg)
tCK(avg)
tCK(avg)
-
DQS output high pulse w idth
-
-
DQS output low pulse w idth
-
-
DQS falling edge to CLK-CLKn rising edge
DQS falling edge from CLK-CLKn rising edge
CLK-CLKn rising edge to DQS output rising edge
DQS w rite preamble
-
1
1
-
-
0.11
-
-
DQS w rite postamble
-
-
CLK-CLKn high-level w idth
0.52
tCK(avg) 1, 2, 3
tCK(avg) 1, 2, 4
CLK-CLKn low -level w idth
tCL
0.52
DQ input setup time relative to DQS in transition
DQ input hold time relative to DQS in transition
Address and control output pulse w idth
tDSI
-
-
-
ns
ns
-
-
-
tDHI
tIPW
tCK(avg)
Notes :
General comment: All timing values w ere measured from vref to vref, unless otherw ise specified.
General comment: All input timing values assume minimum slew rate of 1 V/ns (slew rate measured from Vref +/-125 mV).
General comment: All timing parameters w ith DQS signal are defined on DQS-DQSn crossing point.
General comment: For Address and Control output timing parameters, refer to the Address Timing table.
General comment: tCK = 1/fCK.
General comment: For all signals, the load is CL = 14 pF.
1. This timing value is defined on CLK / CLKn crossing point.
2. Refer to SDRAM DDR2 clock specifications table for more information.
3. tCH(avg) is defined as the average HIGH pulse w idth, as calculated across any consecutive 200 HIGH pulses.
4. tCL(avg) is defined as the average LOW pulse w idth, as calculated across any consecutive 200 LOW pulses.
Copyright © 2008 Marvell
MV-S105424-U0 Rev. B
Page 81
December 6, 2008, Preliminary
Document Classification: Proprietary Information
MARVELL [ MARVELL TECHNOLOGY GROUP LTD. ]
