HYB18T512400AF Datasheet, PDF (73/117 Pages) Infineon Technologies AG – 512-Mbit DDR2 SDRAM

HYB18T512[40/80/16]0AF–[3/3S/3.7/5]
512-Mbit DDR2 SDRAM
Functional Description
T0
T1
T2
T3
T4
Tn
CK, CK
CMD
CKE
Auto
Refresh
tRFC
tXP
tis
CKE can go low one clock after an Auto-Refresh command
When tRFC expires the DRAM is in Precharge Power-Down Mode
Figure 60 Auto-Refresh command to Power-Down entry
T0
T1
T2
T3
T4
T5
T6
T7
CK, CK
CMD
MRS or
EMRS
t_MRD
CKE
Enters Precharge Power-Down Mode
Figure 61 MRS, EMRS command to Power-Down entry
3.26
Other Commands
Valid
Command
ARPD
MRS_PD
3.26.1 No Operation Command
The No Operation Command (NOP) should be used in
cases when the SDRAM is in a idle or a wait state. The
purpose of the No Operation Command is to prevent
the SDRAM from registering any unwanted commands
between operations. A No Operation Command is
registered when CS is LOW with RAS, CAS, and WE
held HIGH at the rising edge of the clock. A No
Operation Command will not terminate a previous
operation that is still executing, such as a burst read or
write cycle.
3.26.2 Deselect Command
The Deselect Command performs the same function as
a No Operation Command. Deselect Command occurs
when CS is brought HIGH, the RAS, CAS, and WE
signals become don’t care.
Data Sheet
73
Rev. 1.3, 2005-01
09112003-SDM9-IQ3P