256M GDDR3 SDRAM
K4J55323QG
Read w/ Auto- : Starts with registration of an READ command with auto precharge enabled and ends
Precharge Enabled when tRP has been met. Once t is met, the bank will be in the idle state.
RP
Write w/ Auto- : Starts with registration of a WRITE command with auto precharge enabled and ends
Precharge Enabled when t has been met. Once t is met, the bank will be in the idle state.
RP
RP
5. The following states must not be interrupted by any executable command ; COMMAND INHIBIT or NOP commands must be applied on each positive
clock edge during these states.
Refreshing : Starts with registration of an AUTO REFRESH command and ends when t is met.
RC
Once t is met, the GDDR3(x32) will be in the all banks idle state.
RC
Accessing Mode : Starts with registration of a LOAD MODE REGISTER command and ends when t
MRD
Register has been met. Once t
is met, the GDDR3(x32) SDRAM will be in the all banks idle state.
MRD
Precharge All : Starts with registration of a PRECHARGE ALL command and ends when t is met.
RP
Once t is met, all banks will be in the idle state.
RP
READ or WRITE : Starts with registration of the ACTIVE command and ends the last valid data nibble.
6. All states and sequences not shown are illegal or reserved.
7. Not bank-specific; requires that all banks are idle, and bursts are not in progress.
8. May or may not be bank-specific ; If multiple banks are to be precharged, each must be in a valid state for precharging.
9. Left blank
10. READs or WRITEs listed in the Command/Action column include READs or WRITEs with auto precharge enabled and READs or WRITEs with auto
precharge disabled.
11. Requires appropriate DM masking.
12. A WRITE command may be applied after the completion of the READ burst.
TRUTH TABLE - CURRENT STATE BANK n - COMMAND TO BANK m
CURRENT STATE
/CS /RAS /CAS /WE
COMMAND/ ACTION
DESELECT (NOP/ continue previous operation)
NO OPERATION (NOP/continue previous operation)
DATA TERMINATOR DISABLE
NOTES
H
L
X
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
X
H
H
X
L
X
H
L
X
H
H
X
H
H
L
Any
Idle
X
H
L
Any Command Otherwise Allowed to Bank m
ACTIVE (Select and activate row)
READ (Select column and start READ burst)
WRITE (Select Column and start WRITE burst)
PRECHARGE
Row Activating,
Active, or
H
H
L
6
6
L
Prechrging
H
H
L
L
L
H
H
L
ACTIVE (Select and activate row)
Read
(Auto-Precharge
Disable)
H
H
L
READ (Select column and start new READ burst)
WRITE (Select column and start WRITE burst)
PRECHARGE
6
6
L
H
H
L
L
L
H
H
L
ACTIVE (Select and activate row)
Write
(Auto-Precharge
Disabled)
H
H
L
READ (Select column and start READ burst)
WRITE (Select column and start new WRITE burst)
PRECHARGE
6, 7
6
L
H
H
L
L
L
H
H
L
ACTIVE (Select and activate row)
Read
(With
Auto-Precharge)
H
H
L
READ (Select column and start new READ burst)
WRITE (Select column and start WRITE burst)
PRECHARGE
6
6
L
H
H
L
L
H
L
L
H
H
L
ACTIVE (Select and activate row)
Write
(With
Auto-Precharge)
H
H
L
READ (Select column and start READ burst)
WRITE (Select column and start new WRITE burst)
PRECHARGE
6
6
L
Note :
1. This table applies when CKEn-1 was HIGH and CKEn is HIGH (see TRUTH TABLE- CKE ) and after t
has been met (if the previous state was
XSNR
self refresh).
2. This table describes alternate bank operation, except where noted (i.e., the current state is for bank n and the commands shown are those allowed
to be issued to bank m, assuming that bank m is in such a state that the given command is allowable). Exceptions are covered in the notes below.
43 of 53
Rev. 1.1 November 2005
SAMSUNG [ SAMSUNG ]
