K4X56163PE Datasheet, PDF (10/48 Pages) Samsung semiconductor – 16M x16 Mobile DDR SDRAM

K4X56163PE-L(F)G
Mobile-DDR SDRAM
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
A10/AP
BA1
BA0
0
0
0
0
0
1
0
1
0
0
1
1
1
X
X
Precharge
Bank A Only
Bank B Only
Bank C Only
Bank D Only
All Banks
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.
10
March 2004