W39V080FA

Publication Release Date: Dec. 13, 2005

- 7 -

Revision A5

6.10 Write Operation Status

The device provides several bits to determine the status of a program or erase operation: DQ5, DQ6,

and DQ7. Each of DQ7 and DQ6 provides a method for determining whether a program or erase

operation is complete or in progress. The device also offers a hardware-based output signal, RY/#BY in

programmer mode, to determine whether an Embedded Program or Erase operation is in progress or

has been completed.

6.10.1 DQ7: #Data Polling

The #Data Polling bit, DQ7, indicates whether an Embedded Program or Erase algorithm is in progress

or completed. Data Polling is valid after the rising edge of the final #WE pulse in the command

sequence.

During the Embedded Program algorithm, the device outputs on DQ7 and the complement of the data

programmed to DQ7. Once the Embedded Program algorithm has completed, the device outputs the

data programmed to DQ7. The system must provide the program address to read valid status

information on DQ7. If a program address falls within a protected sector, #Data Polling on DQ7 is active

for about 1

μS, and then the device returns to the read mode.

During the Embedded Erase algorithm, #Data Polling produces “0” on DQ7. Once the Embedded

Erase algorithm has completed, #Data Polling produces “1” on DQ7. An address within any of the

sectors selected for erasure must be provided to read valid status information on DQ7.

After an erase command sequence is written, if all sectors selected for erasing are protected, #Data

Polling on DQ7 is active for about 100

μS, and then the device returns to the read mode. If not all

selected sectors are protected, the Embedded Erase algorithm erases the unprotected sectors, and

ignores the selected sectors that are protected. However, if the system reads DQ7 at an address within

a protected sector, the status may not be valid.

Just before the completion of an Embedded Program or Erase operation, DQ7 may change

asynchronously with DQ0-DQ6 while Output Enable (#OE) is set to low. That is, the device may

change from providing status information to valid data on DQ7. Depending on when it samples the DQ7

output, the system may read the status or valid data. Even if the device has completed the program or

erase operation and DQ7 has valid data, the data outputs on DQ0-DQ6 may be still invalid. Valid data

on DQ7-DQ0 will appear on successive read cycles.

6.10.2 RY/#BY: Ready/#Busy

The

progress or complete. The

sequence. Since

When the output is low (Busy), the device is actively erasing or programming. When the output is high

(Ready), the device is in the read mode or standby mode.

6.10.3 DQ6: Toggle Bit

Toggle Bit on DQ6 indicates whether an Embedded Program or Erase algorithm is in progress or

complete. Toggle Bit I may be read at any address, and is valid after the rising edge of the final #WE

pulse in the command sequence (before the program or erase operation), and during the sector erase

time-out.

During an Embedded Program or Erase algorithm operation, successive read cycles to any address

cause DQ6 to toggle. The system may use either #OE to control the read cycles. Once the operation

has completed, DQ6 stops toggling.