k4j55323qf-gc Samsung Semiconductor, Inc., k4j55323qf-gc Datasheet - Page 23

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

K4J55323QF-GC
READs
ing column and bank addresses are provided with the READ command and
auto precharge is either enabled or disabled for that burst access. If auto pre-
charge is enabled, the row being accessed is prechrged at the completion of
the burst after t
in the following illustrations, auto precharge is disabled.
address will be available following the CAS Latency after the READ com-
mand. Each subsequent data-out element will be valid nominally at the next
positive or negative strobe edge. READ burst figure shows general timing for
2 of the possible CAS latency settings. The GDDR3(x32) drives the output
data edge aligned to the crossing of CK and /CK and to RDQS. The initial
HIGH transitioning LOW of RDQS is known as the read preamble ; the half
cycle coincident with the last data-out element is known as the read postam-
ble.
ated, the DQs will go High-Z. A detailed explanation of t
skew), t
Output Timing (1) figure. A detailed explanation of t
skew to CK) is shown in Data Output Timing (2) figure.
quent READ command. A continuous flow of data can be maintained. The
first data element from the new burst follows the last element of a completed
burst. The new READ command should be issued x cycles after the first
READ command, where x equals the number of data element nibbles (nibbles
are required by the 4n-prefetch architecture) depending on the burst length.
This is shown in consecutive READ bursts figure. Nonconsecutive read data
is shown for illustration in nonconsecutive READ bursts figure. Full-speed
random read accesses within a page (or pages) can be performed as shown
in Random READ accesses figure. Data from a READ burst cannot be termi-
nated or truncated.
During READ commands the GDDR3 Dram disables its data terminators.
READ bursts are initiated with a READ command, as below figure. The start-
During READ bursts, the valid data-out element from the starting column
Upon completion of a burst, assuming no other commands have been initi-
Data from any READ burst may be concatenated with data from a subse-
DV
(data-out window hold), the valid data window are depicted in Data
RAS(min)
has been met. For the generic READ commands used
AC
(DQS and DQ transition
DQSQ
- 23 -
(valid data-out
A0-A7, A9
A10, A11
256M GDDR3 SDRAM
BA0,1
/RAS
/CAS
/WE
/CS
CKE
A8
/CK
CK
CA = Column Address
BA = Bank Address
EN AP = Enable Auto Precharge
DIS AP = Disable Auto Precharge
READ Command
HIGH
Rev 1.7 (Jan. 2005)
DON’T CARE
DIS AP
EN AP
CA
BA