A29040A Series
Write Operation Status
Several bits, I/O2, I/O3, I/O5, I/O6, and I/O7, are provided in the
A29040A to determine the status of a write operation. Table 5
and the following subsections describe the functions of these
status bits. I/O7, I/O6 and I/O2 each offer a method for
determining whether a program or erase operation is complete
or in progress. These three bits are discussed first.
START
Read I/O7-I/O0
Address = VA
I/O7:
Polling
Data
The
Polling bit, I/O7, indicates to the host system
Data
whether an Embedded Algorithm is in progress or completed,
or whether the device is in Erase Suspend. Polling is
Data
pulse in the program
Yes
valid after the rising edge of the final
or erase command sequence.
I/O7 = Data ?
No
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,
Polling on I/O7 is active for
Data
approximately 2ms, then the device returns to reading array
data.
During the Embedded Erase algorithm,
a "0" on I/O7. When the Embedded Erase algorithm is
complete, or if the device enters the Erase Suspend mode,
Polling produces
Data
Read I/O7 - I/O0
Address = VA
Polling produces a "1" on I/O7.This is analogous to the
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.
Yes
I/O7 = Data ?
After an erase command sequence is written, if all sectors
selected for erasing are protected,
Polling on I/O7 is
Data
No
active for approximately 100ms, 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.
FAIL
PASS
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
Note :
asynchronously with I/O0 - I/O6 while Output Enable (
) is
OE
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.
asserted low. The
Polling Timings (During Embedded
Data
Algorithms) figure in the "AC Characteristics" section illustrates
this. Table 5 shows the outputs for Polling on I/O7.
Data
Polling algorithm.
Figure 3 shows the
Data
Figure 3. Data Polling Algorithm
PRELIMINARY
(August, 2001, Version 0.1)
11
AMIC Technology, Inc.