DDRSDRAM Datasheet, PDF (34/49 Pages) Samsung semiconductor – DDR SDRAM Specification Version 0.61

128Mb DDR SDRAM
Target
5. Functional Truth Table
Current State
PRECHARGE
STANDBY
ACTIVE
STANDBY
READ
CS RAS CAS WE
Address
Command
Action
L H H LX
Burst Stop
ILLEGAL*2
L H L X BA, CA, A10
READ/WRITE ILLEGAL*2
L L H H BA, RA
Active
Bank Active, Latch RA
L L H L BA, A10
PRE/PREA
ILLEGAL*4
L L L HX
Refresh
AUTO-Refresh*5
L L L L Op-Code, Mode-Add MRS
Mode Register Set*5
L H H LX
Burst Stop
NOP
L H L H BA, CA, A10
L H L L BA, CA, A10
L L H H BA, RA
READ/READA ^{Begin Read, Latch CA,}
Determine Auto-Precharge
WRITE/WRITEA ^{Begin Write, Latch CA,}
Determine Auto-Precharge
Active
Bank Active/ILLEGAL*2
L L H L BA, A10
PRE/PREA
Precharge/Precharge All
L L L HX
Refresh
ILLEGAL
L L L L Op-Code, Mode-Add MRS
ILLEGAL
L H H LX
Burst Stop
Terminate Burst
L H L H BA, CA, A10
READ/READA
Terminate Burst, Latch CA,
Begin New Read, Determine
Auto-Precharge*3
L H L L BA, CA, A10
WRITE/WRITEA ILLEGAL
L L H H BA, RA
Active
Bank Active/ILLEGAL*2
L L H L BA, A10
PRE/PREA
Terminate Burst, Precharge
L L L HX
Refresh
ILLEGAL
L L L L Op-Code, Mode-Add MRS
ILLEGAL
Table 9-1. Functional truth table
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REV. 0.61 August 9. '99