AS29CF160T-55TIN
AS29CF160B-55TIN
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
Under both these conditions, the system must issue the reset
command to return the device to reading array data.
Read I/O
7
-I/O
0
0
I/O3: Sector Erase Timer
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 50µs. See also the "Sector Erase Command
Sequence" section.
Read I/O
7
-I/O
(Note 1)
No
Toggle Bit
= Toggle ?
Yes
After the sector erase command sequence is written, the
No
system should read the status on I/O7 (
Polling) or I/O6
Data
I/O5 = 1?
(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 10 shows the outputs for I/O3.
Yes
- I/O
Read I/O
7
0
(Notes 1,2)
Twice
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/O
5
changes to "1". See text.
Figure 6. Toggle Bit Algorithm
Confidential
- 21 of 41 -
Rev.1.0 July 2019
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
