eorex

EM48AM1684LBA

Mar. 2009

www.eorex.com

2. DQM Truth Table

CKE

Command

Symbol

n-1

n

/CS

Data Write/Output Enable

ENB

H

X

H

Data Mask/Output Disable

MASK

H

X

L

Upper Byte Write Enable/Output Enable

BSTH

H

X

L

Read

READ

H

X

L

Read with Auto Pre-charge

READA

H

X

L

Write

WRIT

H

X

L

Write with Auto Pre-charge

WRITA

H

X

L

Bank Activate

ACT

H

X

L

Pre-charge Select Bank

PRE

H

X

L

Pre-charge All Banks

PALL

H

X

L

Mode Register Set

MRS

H

X

L

H = High level, L = Low level, X = High or Low level (Don't care), V = Valid data input

3. CKE Truth Table

CKE

Item

Command

Symbol

n-1

n

/CS

/RAS

/CAS

/WE

Addr.

Activating

Clock Suspend Mode Entry

H

L

X

X

X

X

X

Any

Clock Suspend Mode

L

L

X

X

X

X

X

Clock

Suspend

Clock Suspend Mode Exit

L

H

X

X

X

X

X

Idle

CBR Refresh Command

REF

H

H

L

L

L

H

X

Idle

Self Refresh Entry

SELF

H

L

L

L

L

H

X

L

H

L

H

H

H

X

Self Refresh

Self Refresh Exit

L

H

H

X

X

X

X

Idle

Power Down Entry

H

L

X

X

X

X

X

Power Down

Power Down Exit

L

H

X

X

X

X

X

Remark H = High level, L = Low level, X = High or Low level (Don't care)

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