Harman Kardon AVR 254, Service Manual

Page: 107 / 189

10
Revision 1.9
256M Double Data Rate Synchronous DRAM
A3S56D30ETP
A3S56D40ETP
FUNCTION TRUTH TABLE (continued)
Current State /CS /RAS /CAS /WE Address Command Action Notes
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 ILLEGAL
L H L H BA, CA, A10 READ / READA
Terminate Burst, Latch CA, Begin
Read, Determine Auto-Precharge
3
L H L L BA, CA, A10 WRITE / WRITEA
Terminate Burst, Latch CA, Begin
Write, Determine Auto-Precharge
3
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
L L 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 ILLEGAL
L H L H BA, CA, A10 READ / READA Support Concurrent Auto-Precharge
L H L L BA, CA, A10 WRITE / WRITEA Support Concurrent Auto-Precharge
L L H H BA, RA ACT Bank Active / ILLEGAL 2
L L H L BA, A10 PRE / PREA Precharge / ILLEGAL 2
L L L H X REFA ILLEGAL
L L 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 ILLEGAL
L H L H BA, CA, A10 READ / READA Support Concurrent Auto-Precharge
L H L L BA, CA, A10 WRITE / WRITEA Support Concurrent Auto-Precharge
L L H H BA, RA ACT Bank Active / ILLEGAL 2
L L H L BA, A10 PRE / PREA Precharge / ILLEGAL 2
L L L H X REFA ILLEGAL
L L L L
Op-Code, Mode-
Add
MRS ILLEGAL
WRITE(Auto-
Precharge
Disabled)
READ with
Auto-Precharge
WRITE with
Auto-Precharge
107
AVR254
harman/kardon