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- 47 -
Rev 1.0 (Mar 2005)
512M GDDR3 SDRAM
K4J52324QC-B
TRUTH TABLE - CURRENT STATE BANK
n
- COMMAND TO BANK
n
NOTES :
1. This table applies when CKE
n-1
was HIGH and CKE
n
is HIGH (see CKE Truth Table) and after t
XSNR
has been met
(if the previous state was self refresh).
2. This table is bank-specific, except where noted (i.e., the current state is for a specific bank and the commands shown
are those allowed to be issued to that bank when in that state). Exceptions are covered in the notes below.
3. Current state definitions :
Idle : The bank has been precharged, and t
RP
has been met.
Row Active : A row in the bank has been activated, and t
RCD
has been met.
No data bursts/accesses and no register accesses are in progress.
Read : A READ burst has been initiated, with auto precharge disabled.
Write : A WRITE burst has been initiated, with auto precharge disabled.
4. The following states must not be interrupted by a command issued to the same bank. COMMAND INHIBIT or NOP
commands, or allowable commands to the other bank should be issued on any clock edge occurring during these
states. Allowable commands to the other bank are determined by its current state and truth table- current state bank
n
command to bank
n
. and according to truth table - current state bank
n
-command to bank
m.
Precharging : Starts with registration of a PRECHARGE command and ends when t
RP
is met.
Once t
RP
is met, the bank will be in the idle state.
Row Activating : Starts with registration of an ACTIVE command and ends when t
RCD
is met.
Once t
RCD
is met, the bank will be in the :row active" state.
CURRENT STATE
/CS
/RAS
/CAS
/WE
COMMAND/ ACTION
NOTES
Any
H
X
X
X
DESELECT (NOP/ continue previous operation)
L
H
H
H
NO OPERATION (NOP/continue previous operation)
X
H
L
H
DATA TERMINATOR DISABLE
Idle
L
L
H
H
ACTIVE (Select and activate row)
L
L
L
H
AUTO REFRESH
7
Row Active
L
L
L
L
LOAD MODE REGISTER
7
L
H
L
H
READ (Select column and start READ burst)
10
L
H
L
L
WRITE (Select Column and start WRITE burst)
10
L
L
H
L
PRECHARGE (Deactivate row in bank or banks)
8
Read
(Auto-Precharge
Disable)
L
H
L
H
READ (Select column and start new READ burst)
10
L
H
L
L
WRITE (Select column and start WRITE burst)
10, 12
L
L
H
L
PRECHARGE (Only after the READ burst is complete)
8
Write
(Auto-Precharge
Disabled)
L
H
L
H
READ (Select column and start READ burst)
10, 11
L
H
L
L
WRITE (Select column and start new WRITE burst)
10
L
L
H
L
PRECHARGE (Only after the WRITE burst is complete)
8, 11