256MB, 512MB Unbuffered SODIMM

Rev. 1.2 March 2004

SDRAM

PIN CONFIGURATION DESCRIPTION

Pin

Name

Input Function

CLK

System clock

Active on the positive going edge to sample all inputs.

CS

Chip select

Disables or enables device operation by masking or enabling all inputs except

CLK, CKE and DQM

CKE

Clock enable

Masks system clock to freeze operation from the next clock cycle.

CKE should be enabled at least one cycle prior to new command.

Disable input buffers for power down in standby.

A0 ~ A12

Address

Row/column addresses are multiplexed on the same pins.

Row address : RA0 ~ RA12

Column address : (x16 : CA0 ~ CA9)

BA0 ~ BA1

Bank select address

Selects bank to be activated during row address latch time.

Selects bank for read/write during column address latch time.

RAS

Row address strobe

Latches row addresses on the positive going edge of the CLK with RAS low.

Enables row access & precharge.

CAS

Column address strobe

Latches column addresses on the positive going edge of the CLK with CAS low.

Enables column access.

WE

Write enable

Enables write operation and row precharge.

Latches data in starting from CAS, WE active.

DQM0 ~ 7

Data input/output mask

Blocks data input when DQM active. (Byte masking)

Data input/output

Data inputs/outputs are multiplexed on the same pins.

Power supply/ground

Power and ground for the input buffers and the core logic.