9
Revision 1.9
256M Double Data Rate Synchronous DRAM
A3S56D30ETP
A3S56D40ETP
FUNCTION TRUTH TABLE
Current State /CS /RAS /CAS /WE Address Command Action Notes
IDLE H X X X X DESEL NOP
L H H H X NOP NOP
L H H L BA TERM ILLEGAL 2
L H L X BA, CA, A10 READ / WRITE ILLEGAL 2
L L H H BA, RA ACT Bank Active, Latch RA
L L H L BA, A10 PRE / PREA NOP 4
LL LHX REFA Auto-Refresh 5
LL L L
Op-Code, Mode-
Add
MRS Mode Register Set 5
ROW ACTIVE H X X X X DESEL NOP
L H H H X NOP NOP
L H H L BA TERM ILLEGAL
L H L H BA, CA, A10 READ / READA
Begin Read, Latch CA, Determine
Auto-Precharge
L H L L BA, CA, A10 WRITE / WRITEA
Begin Write, Latch CA, Determine
Auto-Precharge
L L H H BA, RA ACT Bank Active / ILLEGAL 2
L L H L BA, A10 PRE / PREA Precharge / Precharge All
L L L H X REFA ILLEGAL
LL L L
Op-Code, Mode-
Add
MRS ILLEGAL
H X X X X DESEL NOP (Continue Burst to END)
L H H H X NOP NOP (Continue Burst to END)
L H H L BA TERM 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 ACT Bank Active / ILLEGAL 2
L L H L BA, A10 PRE / PREA Terminate Burst, Precharge
L L L H X REFA ILLEGAL
LL L L
Op-Code, Mode-
Add
MRS ILLEGAL
READ(Auto-
Precharge
Disabled)
AVR3600 harman/kardon