GXM Datasheet, PDF (117/244 Pages) National Semiconductor (TI) – Geode™ GXm Processor Integrated x86 Solution with MMX Support

Integrated Functions (Continued)
SDRAM Refresh Cycle
Figure 4-7 shows a SDRAM auto refresh cycle. The mem-
ory controller always precedes the refresh cycle with a
PRE command to all banks.
Page Miss
Figure 4-8 shows a Read/WRT command after a page
miss cycle. In order to program the new row address, a
PRE command must be issued followed by an ACT com-
mand.
SDCLK
CS#
RAS#
CAS#
WE#
MA[10]
Figure 4-7. Auto Refresh Cycle
SDCLK
COMMAND
PRE NOP NOP ACT NOP NOP R/W NOP
tRP
tRCD
ADDRESS
BA
ROW
COL
Figure 4-8. Read/WRT Command to a New Row Address
Revision 3.1
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