K4J52324QC Datasheet, PDF (50/57 Pages) Samsung semiconductor – 512Mbit GDDR3 SDRAM

K4J52324QC-B
512M GDDR3 SDRAM
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.
Read w/ Auto- Precharge Enabled : See following text
Write w/ Auto- Precharge Enabled : See following text
3a. The read with auto precharge enabled or write with auto precharge enabled states can each be broken into two
parts : the access period and the precharge period. For read with auto precharge, the precharge period is defined
as if the same burst was executed with auto precharge disabled and then followed with the earliest possible PRE-
CHARGE command that still accesses all of the data in the burst. For write with auto precharge, the precharge
period begins when tWR ends, with tWR command and ends where the precharge period (or t_RP) begins.
During the precharge period of the read with auto precharge enabled or write with auto precharge enabled states,
ACTIVE, PRECHARGE, READ and WRITE commands to the other bank may be applied. In either case, all other
related Limitations apply (e.g., contention between read data write data must be avoided).
3b. The minimum delay from a READ or WRITE command with auto precharge enabled, to a command to a different
bank is summarized below.
From Command
WRITE w/AP
READ w/AP
To Command
READ or READ w/AP
WRITE or WRITE w/AP
PRECHARGE
ACTIVE
READ or READ w/AP
WRITE or WRITE w/AP
PRECHARGE
ACTIVE
Minimum delay (with concurrent auto precharge)
[WL + (BL/2)] tCK + tWR
(BL/2) * tCK
1 tCK
1 tCK
(BL/2) * tCK
[CLRU + (BL/2)] + 1 - WL * tCK
1 tCK
1 tCK
4. AUTO REFRESH and LOAD MODE REGISTER commands may only be issued when all banks are idle.
5. All states and sequences not shown are illegal or reserved.
6. 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.
7. Requires appropriate DM masking.
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Rev 1.0 (Mar 2005)