A64E06161

3. Partial Array Refresh (PAR) mode

In this mode, customers can turn off section of A64E06161 in

stand-by mode to save standby current. The A64E06161 is

divided into four 4M sections allowing certain section to be

active. The array partition to be refreshed is determined by

the respective bit in the CR register. When

only the portion of the array that is set in the CR register is

refreshed and the data is keep at a certain section of

memory. The Partial Array Refresh (PAR) mode is only

available during standby time (

high, the A64E06161 goes back to operating in full array

refresh. For Partial Array Refresh (PAR) mode to be

activated, the register bit, A4 must be set to a “1” value. To

change the address space of the Partial Array Refresh (PAR)

mode, the CR register must be updated using the CR

register description. If the CR register is not updated after

power on, the A64E06161 will be in its default state and the

whole memory array will be refreshed.

Partial Array Refresh – Entry/Exit

Partial Array Mode/

Deep Power Down Mode

CE or

UB / LB

1us

suspend

ZZ

Figure 2: Partial Array refresh – Entry/Exit

Partial Array Mode Timings

Parameter

Description

Min.

Max.

Unit

ZZ LOW to WE LOW

1

µs

Chip Deselect to ZZ LOW

0

µs

Operation Recovery Time (Deep Power Down Mode only)

200

µs

Deep Power Down Mode Time

10

µs

ZZ LOW to CE LOW

0

1

µs

ZZ LOW to

LD

UB

/

LOW

0

1

µs

Notes:

1. OE and the data pins are in a “don’t care” state while the device is in Partial Array Mode.

2. All other timing parameters are as shown in the switching characteristics section.

4. Temperature Compensated Refresh (TCR) mode

In this mode, the hidden refresh rate can be optimized for the

operating temperature. At higher temperature, the DRAM cell

must be refreshed more often than at lower temperature. By

setting the temperature of operation in CR register, the

refresh rate can be optimized to meet the low standby

current at given operating temperature. There are four

selections (+15

°C, +45°C, +70°C, +85°C) in the CR register

description.

PRELIMINARY

(November, 2004, Version 0.1)

10

AMIC Technology, Corp.