k4j55323qf-gc Samsung Semiconductor, Inc., k4j55323qf-gc Datasheet - Page 38

• Manufacturer Part Number: k4j55323qf-gc
• Description: 256mbit Gddr3 Sdram
• Manufacturer: Samsung Semiconductor, Inc.

Power-Down
K4J55323QF-GC
PRECHARGE
particular bank or the open row in all banks. The bank(s) will be available
for a subsequent row access some specified time (t
CHARGE command is issued. Input A8 determines whether one or all
banks are to be precharged, and in the case where only one bank is to
be precharged, inputs BA0, BA1 select the bank. When all banks are to
be precharged, inputs BA0, BA1 are treated as "Don’t Care." Once a
bank has been precharged, it is in the idle state and must be activated
prior to any READ or WRITE commands being issued to the bank.
POWER-DOWN (CKE NOT ACTIVE)
times an access is in progress; from the issuing of a READ or WRITE
command until completion of the burst. For READs, a burst completion is
defined when the Read Postamble is satisfied; For WRITEs, a burst
completion is defined BL/2 cycles after the Write Postamble is satisfied.
occurs when there is a row active in any bank, this mode is referred to as
active power-down. Entering power-down deactivates the input and out-
put buffers, excluding CK,/CK and CKE. For maximum power savings,
the user has the option of disabling the DLL prior to entering power-
down. However, power-down duration is limited by the refresh require-
ments of the device, so in most applications,the self-refresh mode is pre-
ferred over the DLL-disabled power-down mode.
maintained at the inputs of the GDDR3 SDRAM, while all other input sig-
nals are "Don’t Care."
HIGH (in conjunction with a NOP or DESELECT command). A valid exe-
cutable command may be applied six clock cycle later.
COMMAND
The PRECHARGE command is used to deactivate the open row in a
Unlike SDRAMs,GDDR3(x32) SDRAM requires CKE to be active at all
Power-down is entered when CKE is registered LOW. If power-down
When in power-down, CKE LOW and a stable clock signal must be
The power-down state is synchronously exited when CKE is registered
CKE
/CK
CK
No PEAD/WRITE
access in progress
VALID
T0
t
IS
NOP
T1
Enter power - down mode
NOP
T2
RP
) after the PRE-
- 38 -
Ta0
A0-A7, A9-A11
t
IS
NOP
Ta1
Exit power - down mode
PRECHARGE Command
BA0,1
256M GDDR3 SDRAM
(if A8 is LOW; otherwise "Don’t Care")
/RAS
/CAS
CKE
/WE
/CK
/CS
CK
A8
BA=Bank Address
NOP
Ta2
t
HIGH
PDEX
ALL BANKS
ONE BANK
Rev 1.7 (Jan. 2005)
DON’T CARE
BA
VALID
Ta7