Rev. 1.1 / May. 2005

20

EXTENDED MODE REGISTER SET (EMRS)

The Extended Mode Register controls functions beyond those controlled by the Mode Register; these additional func-

tions include DLL enable/disable, output driver strength selection(optional). These functions are controlled via the bits

shown below. The Extended Mode Register is programmed via the Mode Register Set command ( BA0=1 and BA1=0)

and will retain the stored information until it is programmed again or the device loses power.

The Extended Mode Register must be loaded when all banks are idle and no bursts are in progress, and the controller

must wait the specified time before initiating any subsequent operation. Violating either of these requirements will

result in unspecified operation.

BA1

BA0

A11

A10

A9

A8

A7

A6

A5

A4

A3

A2

A1

A0

0

1

RFU*

DS

RFU*

DS

DS

DLL

A0

DLL enable

0Enable

1Diable

BA0

MRS Type

0MRS

1EMRS

A6

A1

Output Driver Impedance Control

00

Full

0

1

Half

10

RFU*

11

Weak

* All bits in RFU address fields must be programmed to Zero, all other states are reserved for future usage.