K4J55323QF-GC Datasheet, PDF (40/49 Pages) Samsung semiconductor – 256Mbit GDDR3 SDRAM

K4J55323QF-GC
256M GDDR3 SDRAM
TRUTH TABLE - CURRENT STATE BANK n - COMMAND TO BANK n
CURRENT STATE
Any
Idle
Row Active
Read
(Auto-Precharge
Disable)
Write
(Auto-Precharge
Disabled)
/CS /RAS /CAS /WE
COMMAND/ ACTION
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
L
L
H
H ACTIVE (Select and activate row)
L
L
L
H AUTO REFRESH
L
L
L
L LOAD MODE REGISTER
L
H
L
H READ (Select column and start READ burst)
L
H
L
L WRITE (Select Column and start WRITE burst)
L
L
H
L PRECHARGE (Deactivate row in bank or banks)
L
H
L
H READ (Select column and start new READ burst)
L
H
L
L WRITE (Select column and start WRITE burst)
L
L
H
L PRECHARGE (Only after the READ burst is complete)
L
H
L
H READ (Select column and start READ burst)
L
H
L
L WRITE (Select column and start new WRITE burst)
L
L
H
L PRECHARGE (Only after the WRITE burst is complete)
NOTES
13
7
7
10
10
8
10
10, 12
8
10, 11
10
8, 11
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.
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Rev 1.8 (Apr. 2005)