After the sector erase command sequence is written,
the system should read the status on DQ7 (Data# Poll-
ing) or DQ6 (Toggle Bit I) to ensure the device has ac-
cepted the command sequence, and then read DQ3. If
DQ3 is “1”, the internally controlled erase cycle has be-
gun; 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 ac-
cepted. Table 23 shows the outputs for DQ3.
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 µs. See
also the Sector Erase Command section.
Table 23. Write Operation Status
DQ7
DQ5
DQ2
Operation
(Note 2)
DQ6
(Note 1)
DQ3
N/A
1
(Note 2)
RY/BY#
Embedded Program Algorithm
Embedded Erase Algorithm
DQ7#
0
Toggle
Toggle
0
0
No toggle
Toggle
0
0
Standard
Mode
Reading within Erase
Suspended Sector
1
No toggle
0
N/A
Toggle
1
Erase
Suspend Reading within Non-Erase
Data
Data
Data
Data
Data
1
0
Mode
Suspended Sector
Erase-Suspend-Program
DQ7#
Toggle
0
N/A
N/A
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 for more information.
2. DQ7 and DQ2 require a valid address when reading status information. Refer to the appropriate subsection for further details.
52
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June 7, 2006
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