EDI416S4030A

10

White Electronic Designs Corporation • (602) 437-1520 • www.wedc.com

White Electronic Designs

January, 2003

Rev. 2

White Electronic Designs Corp. reserves the right to change products or specifications without notice.

Current

State

Command

Action

Notes

CE# RAS# CAS# WE#

BA

A11, A10/AP-A0

Description

Write

Recovering

with Auto

Precharge

L

L

L

L

OP Code

Mode Register Set

ILLEGAL

L

L

L

H

X

X

Auto or Self Refresh

ILLEGAL

L

L

H

L

X

X

Precharge

ILLEGAL

4

L

L

H

H

BA

Row Address

Bank Activate

ILLEGAL

4

L

H

L

L

BA

Column

Write

ILLEGAL

4,9

L

H

L

H

BA

Column

Read

ILLEGAL

4,9

L

H

H

L

X

X

Burst Termination

L

H

H

H

X

X

No Operation

H

X

X

X

X

X

Device Deselect

Refreshing

L

L

L

L

OP Code

Mode Register Set

ILLEGAL

L

L

L

H

X

X

Auto or Self Refresh

ILLEGAL

L

L

H

L

X

X

Precharge

ILLEGAL

L

L

H

H

BA

Row Address

Bank Activate

ILLEGAL

L

H

L

L

BA

Column

Write

ILLEGAL

L

H

L

H

BA

Column

Read

ILLEGAL

L

H

H

L

X

X

Burst Termination

L

H

H

H

X

X

No Operation

H

X

X

X

X

X

Device Deselect

Mode

Register

Accessing

L

L

L

L

OP Code

Mode Register Set

ILLEGAL

L

L

L

H

X

X

Auto or Self Refresh

ILLEGAL

L

L

H

L

X

X

Precharge

ILLEGAL

L

L

H

H

BA

Row Address

Bank Activate

ILLEGAL

L

H

L

L

BA

Column

Write

ILLEGAL

L

H

L

H

BA

Column

Read

ILLEGAL

L

H

H

L

X

X

Burst Termination

ILLEGAL

L

H

H

H

X

X

No Operation

No Operation; Idle after two clock cycles

H

X

X

X

X

X

Device Deselect

No Operation; Idle after two clock cycles

CURRENT STATE TRUTH TABLE (CONT.)

NOTES:

1.

CKE is assumed to be active (high) in the previous cycle for all entries. The Current State is the state of the bank that the command is being applied to.

2.

All Banks must be idle otherwise it is an illegal action.

3.

If CKE is active (high) the SDRAM starts the Auto (CBR) Refresh operation, if CKE is inactive (low) then the Self Refresh mode is entered.

4.

The Current State refers only to one of the banks, if BA0, BA1 selects this bank then the action is illegal. If BA0, BA1 selects the bank not being referenced by the Current State

then the action may be legal depending on the state of that bank.

5.

If CKE is inactive (low) then the Power Down mode is entered, otherwise there is a No Operation.

6.

7.

8.

Address A10 is used to determine if the Auto Precharge function is activated.

9.

satisfied.