CMP0817BAx-E

CMOS LPRAM

Revision 0.5

Aug. 2006

10

LOW POWER MODES

Address

/CS

/UB, /LB

/WE

tWC

tWR(4)

tBW

tWP(1)

tCW(2)

tAS(3)

tAW

/ZZ

tZZWE

Register Write Start

Register Write

Complete

Register Update

Complete

The register update take place on the rising edge of /ZZ. Once the register is updated, the next time /ZZ goes low, without any

updates to the register starting within the tZZWE max time of 1us, the part will refresh the array selected. The data bus is a

don’t care When /ZZ is low during the register updates.

1. Mode Register Set

A0

A1

A2

A3

A4

A18 ~ A5

Array Refresh Area

Half Selection

Array On/Off

on /ZZ

1

0

Array On/Off on /ZZ

Reduced Memory Size Mode

1

Partial Array Refresh Mode (Default)

0

Type

A3

Note: The RMS(Reduced Memory Size) mode is enabled after

/ZZ goes high and remains enabled after /ZZ goes high. To

change to a different mode, the mode register will have to be

rewritten.

Half Selection (Top / Bottom)

Top

1

Bottom (Default)

0

Type

A2

Array Refresh Area

1

0

½ Array

0

1

1

0

A1

¼ Array

1

Full Array (Default)

0

Type

A0

2. MRS Update

Reduced Memory Size Mode

1

Partial Array Refresh Mode (Default)

0

Type

A3

1. RFU : Reserved for the Future Use