Document Number: 002-00870 Rev.*K

Page 38 of 56

S29AS008J

12.6

DQ5: Exceeded Timing Limits

DQ5 indicates whether the program or erase time has exceeded a specified internal pulse count limit. Under these conditions DQ5

produces a 1. This is a failure condition that indicates the program or erase cycle was not successfully completed.

The DQ5 failure condition may appear if the system tries to program a 1 to a location that is previously programmed to 0. Only an

erase operation can change a 0 back to a 1. Under this condition, the device halts the operation, and when the operation has

exceeded the timing limits, DQ5 produces a 1.

Under both these conditions, the system must issue the reset command to return the device to reading array data.

12.7

DQ3: Sector Erase Timer

After writing a sector erase command sequence, the system may read DQ3 to determine whether or not an erase operation has

begun. (The sector erase timer does not apply to the chip erase command.) If additional sectors are selected for erasure, the entire

time-out also applies after each additional sector erase command. When the time-out is complete, DQ3 switches from 0 to 1. The

system may ignore DQ3 if the system can guarantee that the time between additional sector erase commands will always be less

than 50

s. See also Sector Erase Command Sequence on page 28.

After the sector erase command sequence is written, the system should read the status on DQ7 (Data# Polling) or DQ6 (Toggle Bit

I) to ensure the device has accepted the command sequence, and then read DQ3. If DQ3 is 1, the internally controlled erase cycle

has begun; all further commands (other than Erase Suspend) are ignored until the erase operation is complete. If DQ3 is 0, the

device will accept additional sector erase commands. To ensure the command has been accepted, the system software should

check the status of DQ3 prior to and following each subsequent sector erase command. If DQ3 is high on the second status check,

the last command might not have been accepted. Table shows the outputs for DQ3.

Notes

1. DQ5 switches to 1 when an Embedded Program or Embedded Erase operation has exceeded the maximum timing limits. See DQ5: Exceeded Timing Limits

on page 38 for more information.

2. DQ7 and DQ2 require a valid address when reading status information. Refer to the appropriate subsection for further details.

Write Operation Status

Operation

DQ7

(Note 2)

DQ6

DQ5

(Note 1)

DQ3

DQ2

(Note 2)

RY/BY#

Standard

Mode

Embedded Program Algorithm

DQ7#

Toggle

0

N/A

No toggle

0

Embedded Erase Algorithm

0

Toggle

0

1

Toggle

0

Erase

Suspend

Mode

Reading within Erase

Suspended Sector

1

No toggle

0

N/A

Toggle

1

Reading within Non-Erase

Suspended Sector

Data

Data

Data

Data

Data

1

Erase-Suspend-Program

DQ7#

Toggle

0

N/A

N/A

0