M48Z35AVPC View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

M48Z35AVPC

5.0V or 3.3V, 256Kbit (32Kbit x 8) ZEROPOWER® SRAM

STMicroelectronics 

Operating modes

M48Z35AV

Also, as VCC rises, the battery voltage is checked. If the voltage is less than approximately

2.5V, an internal Battery Not OK (BOK) flag will be set. The BOK flag can be checked after

power up. If the BOK flag is set, the first WRITE attempted will be blocked. The flag is

automatically cleared after the first WRITE, and normal RAM operation resumes. Figure 8

illustrates how a BOK check routine could be structured.

For more information on Battery Storage Life refer to the Application Note AN1012.

Figure 8. BOK check routine example

POWER-UP

READ DATA

AT ANY ADDRESS

WRITE DATA

COMPLEMENT BACK

TO SAME ADDRESS

READ DATA

AT SAME

ADDRESS AGAIN

IS DATA

COMPLEMENT

OF FIRST

READ?

(BATTERY OK) YES

WRITE ORIGINAL

DATA BACK TO

SAME ADDRESS

NO (BATTERY LOW)

NOTIFY SYSTEM

OF LOW BATTERY

(DATA MAY BE

CORRUPTED)

CONTINUE

AI00607

12/24

Share Link: