RMLD232UAW datasheet(10/50 Pages) EMLSI

10 / 50 page

Rev 0.7

64Mb Low Power DDR SDRAM

Advanced

Precharge

The precharge command is used to precharge or close a bank that has been activated. The precharge command is issued when CS,

RAS and WE are low and CAS is high at the rising edge of the clock. The precharge command can be used to precharge each bank

respectively or all banks simultaneously. The bank select addresses(BA0, BA1) are used to define which bank is precharged when

the command is initiated. For write cycle, tWR(min.) must be satisfied until the precharge command can be issued. After tRP from the

precharge, an active command to the same bank can be initiated.

Bank selection for precharge by Bank Address bits

No Operation(NOP) & Device Deselect

The device should be deselected by deactivating the CS signal. In this mode DDR SDRAM should ignore all the control inputs. The

DDR SDRAMs are put in NOP mode when CS is active and by deactivating RAS, CAS and WE. Both Device Deselect and NOP com-

mand can not affect operation already in progress. So even if the device is deselected or NOP command is issued under operation,

operation will be complete.

A10/AP

BA1

BA0

Precharge

Bank A Only

Bank B Only

Bank C Only

Bank D Only

All Banks

RMLD232UAW Datasheet(PDF) 10 Page - Emerging Memory & Logic Solutions Inc