K7I643682M_07 Datasheet, PDF (6/18 Pages) Samsung semiconductor – 2Mx36 & 4Mx18 DDRII CIO b2 SRAM

K7I643682M
K7I641882M
2Mx36 & 4Mx18 DDRII CIO b2 SRAM
GENERAL DESCRIPTION
The K7I643682M and K7I641882M are 75,497,472-bits DDR Common I/O Synchronous Pipelined Burst SRAMs.
They are organized as 2,097,152 words by 36bits for K7I643682M and 4,194,304 words by 18 bits for K7I641882M.
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 and write address are 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 fixed to 2-bit sequential for both read and write operations.
Synchronous pipeline read and late write enable high speed operations.
Simple depth expansion is accomplished by using LD for port selection.
Byte write operation is supported with BW0 and BW1 (BW2 and BW3) pins for x18 (x36) device.
IEEE 1149.1 serial boundary scan (JTAG) simplifies monitoring package pads attachment status with system.
The K7I643682M and K7I641882M 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.
Read Operations
Read cycles are initiated by initiating R/W as high 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 data words with each read command.
The first pipelined data is transferred 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 initiated 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 instead of C and C.
When the LD is disabled after a read operation, the K7I643682M and K7I641882M 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 R/W as low at the rising edge of the positive input clock K.
Address is presented and stored in the write address register synchronized with next K clock.
For 2-bit burst DDR operation, it will write two 36-bit or 18-bit data words with each write command.
The first "late writed" data is transferred and registered in to the device synchronous with next K clock rising edge.
Next burst data is transferred and registered synchronous with following K clock rising edge.
Continuous write operations are initiated with K rising edge.
And "late writed" data is presented to the device on every rising edge of both K and K clocks.
When the LD is disabled, the K7I643682M and K7I641882M will enter into deselect mode.
The device disregards input data presented on the same cycle W disabled.
The K7I643682M and K7I641882M support byte write operations.
With activating BW0 or BW1 (BW2 or BW3) in write cycle, only one byte of input data is presented.
In K7I641882M, BW0 controls write operation to D0:D8, BW1 controls write operation to D9:D17.
And in K7I643682M BW2 controls write operation to D18:D26, BW3 controls write operation to D27:D35.
Single Clock Mode
K7I643682M and K7I641882M can be operated with the single clock pair K and K, instead of C or C for output clocks.
To operate these devices in single clock mode, C and C must be tied high during power up
and must be maintained high during operation.
After power up, this device can′t change to or from single clock mode.
System flight time and clock skew could not be compensated in this mode.
Rev. 1.3 March 2007
-6-