AS29LV800

®

3/22/01; V.1.0

Alliance Semiconductor

P. 10 of 25

March 2001

Status operations

Write operation status

DQ2 toggles when an erase-suspended sector is read repeatedly.

DQ6 toggles when any address is read repeatedly.

DQ2 = 1 if byte address being programmed is read during erase-suspend program mode.

DATA polling (DQ7)

Only active during automated on-chip algorithms or sector erase time outs. DQ7 reflects

complement of data last written when read during the automated on-chip program algorithm (0

during erase algorithm); reflects true data when read after completion of an automated on-chip

program algorithm (1 after completion of erase agorithm).

Toggle bit 1 (DQ6)

Active during automated on-chip algorithms or sector erase time outs. DQ6 toggles when CE or OE

toggles, or an Erase Resume command is invoked. DQ6 is valid after the rising edge of the fourth

pulse of WE during programming; after the rising edge of the sixth WE pulse during chip erase;

after the last rising edge of the sector erase WE pulse for sector erase. For protected sectors,

DQ6 toggles for <1 µs during program mode writes, and <5 µs during erase (if all selected sectors

are protected).

Exceeding time limit

(DQ5)

Indicates unsuccessful completion of program/erase operation (DQ5 = 1). DATA polling remains

active. If DQ5 = 1 during chip erase, all or some sectors are defective; during byte programming or

sector erase, the sector is defective (in this case, reset the device and execute a program or erase

command sequence to continue working with functional sectors). Attempting to program 0 to 1

will set DQ5 = 1.

Sector erase timer

(DQ3)

Checks whether sector erase timer window is open. If DQ3 = 1, erase is in progress; no commands

will be accepted. If DQ3 = 0, the device will accept sector erase commands. Check DQ3 before and

after each Sector Erase command to verify that the command was accepted.

Toggle bit 2 (DQ2)

During sector erase, DQ2 toggles with OE or CE only during an attempt to read a sector being

erased. During chip erase, DQ2 toggles with OE or CE for all addresses. If DQ5 = 1, DQ2 toggles

only at sector addresses where failure occurred, and will not toggle at other sector addresses. Use

DQ2 in conjunction with DQ6 to determine whether device is in auto erase or erase suspend

mode.

Status

DQ7

DQ6

DQ5

DQ3

DQ2

RY/BY

Standard mode

Auto programming

DQ7

Toggle

0

N/A

No toggle

0

Program/erase in auto erase

0

Toggle

0

1

0

Erase suspend mode

Read erasing sector

1

No toggle

0

N/A

Toggle

1

Read non-erasing sector

Data

Data

Data

Data

Data

1

Program in erase suspend

DQ7

Toggle

0

N/A

Toggle

†

0

Exceeded time limits

Auto programming (byte)

DQ7

Toggle

1

N/A

No toggle

1

Program/erase in auto erase

0

Toggle

1

N/A

Toggle

†

1

Program in erase suspend

(non-erase suspended sector)

DQ7

Toggle

1

N/A

No toggle

1