AS29CF160T-55TIN
AS29CF160B-55TIN
Write Operation Status
Several bits, I/O2, I/O3, I/O5, I/O6, I/O7, RY/
the AS29CF160T/B-55TIN to determine the status of a
are provided in
BY
START
write operation. Table
subsections describe the
10
and
the
following
functions of these status bits. I/O7, I/O6 and RY/
each
BY
offer a method for determining whether a program or erase
operation is complete or in progress. These three bits are
discussed first.
Read I/O
Address = VA
7-I/O0
I/O7:
Polling
Data
The
Polling bit, I/O7, indicates to the host system
Data
Yes
whether an Embedded Algorithm is in progress or completed,
I/O7
= Data ?
No
or whether the device is in Erase Suspend. Polling is
Data
pulse in the
valid after the rising edge of the final
program or erase command sequence.
WE
During the Embedded Program algorithm, the device outputs
on I/O7 the complement of the datum programmed to I/O7.
This I/O7 status also applies to programming during
Erase Suspend. When the Embedded Program
algorithm is complete, the device outputs the datum
programmed to I/O7. The system must provide the program
address to read valid status information on I/O7. If a
program address falls within a
No
I/O5 = 1?
Yes
protected sector,
approximately 2µs, then the device returns to reading array
data.
Polling on I/O7 is active for
Data
Read I/O
Address = VA
7
- I/O0
During
the
Embedded
Erase
algorithm,
Data
Polling produces a "0" on I/O7. When the Embedded Erase
algorithm is complete, or if the device enters the Erase
Suspend mode,
Yes
Polling produces a "1" on I/O7.This is analogous to the
Data
I/O7
= Data ?
complement/true datum output described for the Embedded
Program algorithm: the erase function changes all the bits in
a sector to "1"; prior to this, the device outputs the
"complement," or "0." The system must provide an address
within any of the sectors selected for erasure to read valid
status information on I/O7.
No
After an erase command sequence is written, if all sectors
FAIL
PASS
selected for erasing are protected,
Polling on I/O7 is
Data
active for approximately 100µs, then the device returns to
reading array data. If not all selected sectors are protected,
the Embedded Erase algorithm erases the unprotected
sectors, and ignores the selected sectors that are protected.
When the system detects I/O7 has changed from the
complement to true data, it can read valid data at I/O7 - I/O0
on the following read cycles. This is because I/O7 may
change asynchronously with I/O0 - I/O6 while Output Enable
Note :
1. VA = Valid address for programming. During a sector
erase operation, a valid address is an address within any
sector selected for erasure. During chip erase, a valid
address is any non-protected sector address.
2. I/O7 should be rechecked even if I/O5 = "1" because
I/O7 may change simultaneously with I/O5.
(
) is asserted low. The
Polling Timings (During
Data
OE
Embedded Algorithms) figure in the "AC Characteristics"
section illustrates this. Table 10 shows the outputs for
Figure 5. Data Polling Algorithm
Data
Polling algorithm.
Polling on I/O7. Figure 5 shows the
Data
Confidential
- 19 of 41 -
Rev.1.0 July 2019
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
