K7R643682M SAMSUNG [Samsung semiconductor], K7R643682M Datasheet - Page 6

• Manufacturer Part Number: K7R643682M
• Description: 2Mx36 & 4Mx18 & 8Mx9 QDRTM II b2 SRAM
• Manufacturer: SAMSUNG [Samsung semiconductor]

GENERAL DESCRIPTION
Read Operations
Read cycles are initiated by activating R at the rising edge of the positive input clock K.
Address is presented and stored in the read address register synchronized with K clock.
For 2-bit burst DDR operation, it will access two 36-bit or 18-bit or 9-bit data words with each read command.
The first pipelined data is transfered out of the device triggered by C clock following next K clock rising edge.
Next burst data is triggered by the rising edge of following C clock rising edge.
Continuous read operations are initated with K clock rising edge.
And pipelined data are transferred out of device on every rising edge of both C and C clocks.
In case C and C tied to high, output data are triggered by K and K insted of C and C.
When the R is disabled after a read operation, the K7R643682M,K7R641882M and K7R640982M will first complete burst read
operation before entering into deselect mode at the next K clock rising edge.
Then output drivers disabled automatically to high impedance state.
Write Operations
Write cycles are initiated by activating W at the rising edge of the positive input clock K.
Address is presented and stored in the write address register synchronized with following K clock.
For 2-bit burst DDR operation, it will write two 36-bit or 18-bit or 9-bit data words with each write command.
The first "early" data is transfered and registered in to the device synchronous with same K clock rising edge with W presented.
Next burst data is transfered and registered synchronous with following K clock rising edge.
Continuous write operations are initated with K rising edge.
And "early writed" data is presented to the device on every rising edge of both K and K clocks.
When the W is disabled, the K7R643682M, K7R641882M, and K7R640982M will enter into deselect mode.
The device disregards input data presented on the same cycle W disabled.
The K7R643682M, K7R641882M and K7R640982M support byte write operations.
With activating BW
In K7R641882M, BW
And in K7R643682M BW
And in K7R640982M BW controls write operation to D0:D8.
The K7R643682M,K7R641882M and K7R640982M are 75,497,472-bits QDR(Quad Data Rate)
Synchronous Pipelined Burst SRAMs.
They are organized as 2,097,152 words by 36bits for K7R643682M, 4,194,304 words by 18 bits for K7R641882M and
8,388,608 words by 9bits for K7R640982M.
The QDR operation is possible by supporting DDR read and write operations through separate data output and input ports
with the same cycle. Memory bandwidth is maxmized as data can be transfered into sram on every rising edge of K and K,
and transfered out of sram on every rising edge of C and C.
And totally independent read and write ports eliminate the need for high speed bus turn around.
Address, data inputs, and all control signals are synchronized to the input clock ( K or K ).
Normally data outputs are synchronized to output clocks ( C and C ), but when C and C are tied high,
the data outputs are synchronized to the input clocks ( K and K ).
Read data are referenced to echo clock ( CQ or CQ ) outputs.
Read address is registered on rising edges of the input K clocks,
and write address is registered on rising edges of the input K clocks.
Common address bus is used to access address both for read and write operations.
The internal burst counter is fiexd to 2-bit sequential for both read and write operations.
Synchronous pipeline read and early write enable high speed operations.
Simple depth expansion is accomplished by using R and W for port selection.
Byte write operation is supported with BW
IEEE 1149.1 serial boundary scan (JTAG) simplifies monitoriing package pads attachment status with system.
The K7R643682M,K7R641882M and K7R640982M are implemented with SAMSUNG's high performance 6T CMOS technology
and is available in 165pin FBGA packages. Multiple power and ground pins minimize ground bounce.
K7R643682M
K7R641882M
K7R640982M
0
or BW
0
controls write operation to D0:D8, BW
2
1
controls write operation to D18:D26, BW
( BW
2
or BW
3 )
0
and BW
in write cycle, only one byte of input data is presented.
1
( BW
2Mx36 & 4Mx18 & 8Mx9 QDR
2
and BW
1
controls write operation to D9:D17.
- 6 -
3)
3
controls write operation to D27:D35.
pins for x18 ( x36 ) device and only BW pin for x9 device.
TM
Preliminary
II b2 SRAM
Oct. 2004
Rev 0.5