AM29PL320D SPANSION [SPANSION], AM29PL320D Datasheet - Page 31

• Manufacturer Part Number: AM29PL320D
• Description: 32 Megabit (2 M x 16-Bit/1 M x 32-Bit) CMOS 3.0 Volt-only High Performance Page Mode Flash Memory
• Manufacturer: SPANSION [SPANSION]

October 2, 2003
Notes:
1. Read toggle bit twice to determine whether or not it is
2. Recheck toggle bit because it may stop toggling as DQ5
toggling. See text.
changes to “1”. See text.
No
Figure 6. Toggle Bit Algorithm
Complete, Write
Reset Command
Read DQ7–DQ0
Read DQ7–DQ0
Read DQ7–DQ0
Program/Erase
Operation Not
Toggle Bit
Toggle Bit
DQ5 = 1?
= Toggle?
= Toggle?
START
Twice
Yes
Yes
Yes
(Notes
1, 2)
(Note 1)
Operation Complete
No
No
Program/Erase
Am29PL320D
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.
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 addi-
tional 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 addi-
tional sector erase commands will always be less than
50 µs. See also the “Write Operation Status” section.
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
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 com-
plete. 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 15 shows the outputs for DQ3.
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