EDS2504ACTA View Datasheet(PDF) - Elpida Memory, Inc

Part Name

Description

View to exact match

EDS2504ACTA

256M bits SDRAM

Elpida Memory, Inc 

EDS2504ACTA/08ACTA/16ACTA, EDS2504APTA/08APTA/16APTA

Command Operation

Command Truth Table

The SDRAM recognizes the following commands specified by the /CS, /RAS, /CAS, /WE and address pins.

CKE

Function

Symbol n – 1 n

Device deselect

DESL

H

×

No operation

NOP

H

×

Burst stop

BST

H

×

Read

READ

H

×

Read with auto precharge

READA H

×

Write

WRIT

H

×

Write with auto precharge

WRITA H

×

Bank activate

ACT

H

×

Precharge select bank

PRE

H

×

Precharge all banks

PALL

H

×

Mode register set

MRS

H

×

Remark: H: VIH. L: VIL. ×: VIH or VIL

/CS

/RAS /CAS /WE BA1,BA0 A10 A0 to A12

H

×

×

×

×

×

×

L

H

H

H

×

×

×

L

H

H

L

×

×

×

L

H

L

H

V

L

V

L

H

L

H

V

H

V

L

H

L

L

V

L

V

L

H

L

L

V

H

V

L

L

H

H

V

V

V

L

L

H

L

V

L

×

L

L

H

L

×

H

×

L

L

L

L

L

L

V

Device deselect command [DESL]

When this command is set (/CS is High), the SDRAM ignore command input at the clock. However, the internal

status is held.

No operation [NOP]

This command is not an execution command. However, the internal operations continue.

Burst stop command [BST]

This command can stop the current burst operation.

Column address strobe and read command [READ]

This command starts a read operation. In addition, the start address of burst read is determined by the column

address (see Address Pins Table in Pin Function) and the bank select address. After the read operation, the output

buffer becomes High-Z.

Read with auto-precharge [READA]

This command automatically performs a precharge operation after a burst read with a burst length of 1, 2, 4 or 8.

Column address strobe and write command [WRIT]

This command starts a write operation. When the burst write mode is selected, the column address (see Address

Pins Table in Pin Function) and the bank select address (BA0, BA1) become the burst write start address. When the

single write mode is selected, data is only written to the location specified by the column address (see Address Pins

Table in Pin Function) and the bank select address (BA0, BA1).

Write with auto-precharge [WRITA]

This command automatically performs a precharge operation after a burst write with a length of 1, 2, 4 or 8, or after a

single write operation.

Data Sheet E0110E30 (Ver. 3.0)

15

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