A29400 Series
I/O5: Exceeded Timing Limits
I/O5 indicates whether the program or erase time has
exceeded a specified internal pulse count limit. Under
these conditions I/O5 produces a "1." This is a failure
condition that indicates the program or erase cycle was
not successfully completed.
The I/O5 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,
I/O5 produces a "1."
START
Read I/O7-I/O0
Read I/O7-I/O0
(Note 1)
No
Under both these conditions, the system must issue the
reset command to return the device to reading array data.
I/O3: Sector Erase Timer
Toggle Bit
= Toggle ?
After writing a sector erase command sequence, the
system may read I/O3 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, I/O3 switches from "0" to
"1." The system may ignore I/O3 if the system can
guarantee that the time between additional sector erase
commands will always be less than 50ms. See also the
"Sector Erase Command Sequence" section.
Yes
I/O5 = 1?
Yes
No
Read I/O7 - I/O0
After the sector erase command sequence is written, the
(Notes 1,2)
Twice
system should read the status on I/O7 (
Polling) or
Data
I/O6 (Toggle Bit 1) to ensure the device has accepted the
command sequence, and then read I/O3. If I/O3 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 I/O3 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 I/O3 prior to and following each
subsequent sector erase command. If I/O3 is high on the
second status check, the last command might not have
been accepted. Table 6 shows the outputs for I/O3.
No
Toggle Bit
= Toggle ?
Yes
Program/Erase
Operation Not
Commplete, Write
Reset Command
Program/Erase
Operation Complete
Notes :
1. Read toggle bit twice to determine whether or not it is
toggling. See text.
2. Recheck toggle bit because it may stop toggling as I/O5
changes to "1". See text.
Figure 5. Toggle Bit Algorithm
PRELIMINARY
(February, 2001, Version 0.1)
15
AMIC Technology, Inc.
AMICC [ AMIC TECHNOLOGY ]
