k4h280438d Samsung Semiconductor, Inc., k4h280438d Datasheet - Page 19

• Manufacturer Part Number: k4h280438d
• Description: 128mb D-die X4/8 Ddr Sdram
• Manufacturer: Samsung Semiconductor, Inc.

128Mb D-die(x4/8) DDR SDRAM
The essential functionality that is required for the DDR SDRAM device is described in this chapter
command is issued by asserting CS and CAS low while holding RAS and WE high at the rising edge of the
clock(CK) after tRCD from the bank activation. The address inputs (A0~A9) determine the starting address for
the Burst. The Mode Register sets type of burst(Sequential or interleave) and burst length(2, 4, 8). The first
output data is available after the CAS Latency from the READ command, and the consecutive data are pre-
sented on the falling and rising edge of Data Strobe(DQS) adopted by DDR SDRAM until the burst length is
completed.
3.3 Essential Functionality for DDR SDRAM
3.3.1 Burst Read Operation
CAS Latency=2
CAS Latency=2.5
Burst Read operation in DDR SDRAM is in the same manner as the current SDRAM such that the Burst read
< Burst Length=4, CAS Latency= 2, 2.5 >
Command
CK
CK
DQS
DQ s
DQS
DQ s
READ A
0
NOP
Figure 9. Burst read operation timing
1
t
RPRE
NOP
Dout 0 Dout 1 Dout 2 Dout 3
2
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Dout 0 Dout 1 Dout 2 Dout 3
NOP
3
t
RPST
NOP
4
NOP
5
REV. 0.3 Jan.31. 2001
NOP
6
NOP
7
NOP
8