IS43R16320B
IC43R16320B
Current state
/CS
H
/RAS /CAS /WE Address
Command
DESL
Operation
NOP
Next state
Write with auto-
pre-charge*10
×
×
×
×
Precharging
L
L
L
L
L
L
L
H
H
H
H
L
H
H
L
H
L
×
NOP
NOP
Precharging
×
BST
ILLEGAL
—
—
—
—
—
—
H
L
BA, CA, A10
BA, CA, A10
BA, RA
BA, A10
×
READ/READA
WRIT/WRIT A
ACT
ILLEGAL*14
ILLEGAL*14
ILLEGAL*11, 14
ILLEGAL*11, 14
ILLEGAL
L
H
H
L
H
L
L
PRE, PALL
L
×
Remark: H: VIH. L: VIL. ×: VIH or VIL
Notes: 1. The DDR SDRAM is in "Precharging" state for tRP after precharge command is issued.
2. The DDR SDRAM reaches "IDLE" state tRP after precharge command is issued.
3. The DDR SDRAM is in "Refresh" state for tRFC after auto-refresh command is issued.
4. The DDR SDRAM is in "Activating" state for tRCD after ACT command is issued.
5. The DDR SDRAM is in "Active" state after "Activating" is completed.
6. The DDR SDRAM is in "READ" state until burst data have been output and DQ output circuits are turned
off.
7. The DDR SDRAM is in "READ with auto-precharge" from READA command until burst data has been
output and DQ output circuits are turned off.
8. The DDR SDRAM is in "WRITE" state from WRIT command to the last burst data are input.
9. The DDR SDRAM is in "Write recovering" for tWR after the last data are input.
10. The DDR SDRAM is in "Write with auto-precharge" until tWR after the last data has been input.
11. This command may be issued for other banks, depending on the state of the banks.
12. All banks must be in "IDLE".
13. Before executing a write command to stop the preceding burst read operation, BST command must be
issued.
14. The DDR SDRAM supports the concurrent auto-precharge feature, a read with auto-precharge enabled,or
a write with auto-precharge enabled, may be followed by any column command to other banks, as long as
that command does not interrupt the read or write data transfer, and all other related limitations apply.
(E.g. Conflict between READ data and WRITE data must be avoided.)
The minimum delay from a read or write command with auto precharge enabled, to a command to a
different bank, is summarized below.
To command (different bank, non-
interrupting command)
Minimum delay
(Concurrent AP supported)
From command
Read w/AP
Units
tCK
tCK
tCK
tCK
tCK
tCK
Read or Read w/AP
Write or Write w/AP
Precharge or Activate
Read or Read w/AP
Write or Write w/AP
Precharge or Activate
BL/2
CL(rounded up)+ (BL/2)
1
Write w/AP
1 + (BL/2) + tWTR
BL/2
1
18
Integrated Silicon Solution, Inc. — www.issi.com
Rev. 00B
06/11/08
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
