k7r321882c Samsung Semiconductor, Inc., k7r321882c Datasheet - Page 7

• Manufacturer Part Number: k7r321882c
• Description: 1mx36-bit, 2mx18-bit, 4mx9-bit Qdrtm Ii B2 Sram
• Manufacturer: Samsung Semiconductor, Inc.

K7R323682C
K7R320982C
K7R321882C
GENERAL DESCRIPTION
Read Operations
Write Operations
The K7R323682C,K7R321882C and K7R320982C are 37,748,736-bits QDR (Quad Data Rate) Synchronous Pipelined Burst
SRAMs. They are organized as 1,048,576 words by 36bits for K7R323682C, 2,097,152 words by 18 bits for K7R321882C and
4,194,304 words by 9bits for K7R320982C.
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 maximized as data can be transferred into SRAM on every rising edge of K and K, and transferred
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 fixed 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
pins for x18 (x36) device and only BW pin for x9 device.
IEEE 1149.1 serial boundary scan (JTAG) simplifies monitoring package pads attachment status with system.
The K7R323682C,K7R321882C and K7R320982C 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 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 transferred out of the device triggered by C clock following next K clock rising edge. Next burst data is trig-
gered by the rising edge of following C clock rising edge. Continuous read operations are initiated with K clock rising edge. And pipe-
lined 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 R is disabled after a read operation, the K7R323682C,K7R321882C and K7R320982C will first complete burst read opera-
tion before entering into deselect mode at the next K clock rising edge. Then output drivers disabled automatically to high impedance
state.
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 transferred and registered in to the device synchronous with same K clock rising edge with W presented. Next
burst data is transferred and registered synchronous with following K clock rising edge. Continuous write operations are initiated with
K rising edge. And “early write” data is presented to the device on every rising edge of both K and K clocks.
When the W is disabled, the K7R323682C,K7R321882C and K7R320982C will enter into deselect mode. The device disregards
input data presented on the same cycle W disabled.
The K7R323682C, K7R321882C and K7R320982C support byte write operations. With activating BW
cycle, only one byte of input data is presented. In K7R321882C, BW
to D9:D17. And in K7R323682C BW
K7R320982C BW controls write operation to D0:D8.
2
controls write operation to D18:D26, BW
1Mx36 & 2Mx18 & 4Mx9 QDR
- 7 -
0
controls write operation to D0:D8, BW
3
controls write operation to D27:D35. And in
Rev. 1.1 August 2006
0
or BW
0
TM
1
and BW
controls write operation
1
(BW
II b2 SRAM
2
1
or BW
(BW
2
3)
and BW
in write
3)