Am29F016

15

Write Operation Status

Table 6.

Write Operation Status

Notes:

1. Performing successive read operations from the erase-suspended sector will cause DQ2 to toggle.

2. Performing successive read operations from any address will cause DQ6 to toggle.

3. Reading the byte address being programmed while in the erase-suspend program mode will indicate logic ‘1’ at the DQ2 bit.

However, successive reads from the erase-suspended sector will cause DQ2 to toggle.

DQ7

Data Polling

The Am29F016 device features Data Polling as a

method to indicate to the host that the embedded

algorithms are in progress or completed. During the

Embedded Program Algorithm, an attempt to read the

device will produce the complement of the data last

written to DQ7. Upon completion of the Embedded

Program Algorithm, an attempt to read the device will

produce the true data last written to DQ7. During the

Embedded Erase Algorithm, an attempt to read the

device will produce a “0” at the DQ7 output. Upon

completion of the Embedded Erase Algorithm an at-

tempt to read the device will produce a “1” at the DQ7

output. The flowchart for Data Polling (DQ7) is shown

in Figure 3.

Data Polling will also flag the entry into Erase Suspend.

DQ7 will switch “0” to “1” at the start of the Erase Sus-

pend mode. Please note that the address of an erasing

sector must be applied in order to observe DQ7 in the

Erase Suspend Mode.

During Program in Erase Suspend, Data Polling will

perform the same as in regular program execution out-

side of the suspend mode.

For chip erase, the Data Polling is valid after the rising

edge of the sixth WE pulse in the six write pulse

sequence. For sector erase, the Data Polling is valid

after the last rising edge of the sector erase WE pulse.

Data Polling must be performed at sector addresses

within any of the sectors being erased and not a sector

that is within a protected sector group. Otherwise, the

status may not be valid.

Just prior to the completion of Embedded Algorithm op-

erations DQ7 may change asynchronously while the

output enable (OE) is asserted low. This means that

the device is driving status information on DQ7 at one

instant of time and then that byte’s valid data at the next

instant of time. Depending on when the system sam-

ples the DQ7 output, it may read the status or valid

data. Even if the device has completed the Embedded

Algorithm operations and DQ7 has a valid data, the

data outputs on DQ0–DQ6 may be still invalid. The

valid data on DQ0–DQ7 can be read on the successive

read attempts.

The Data Polling feature is only active during the Em-

bedded Programming Algorithm, Embedded Erase Al-

gorithm, Erase Suspend, erase-suspend-program

mode, or sector erase time-out (see Table 6).

See Figure 11 for the Data Polling timing specifications

and diagrams.

Status

DQ7

DQ6

DQ5

DQ3

DQ2

In Progress

Byte Program in Embedded Program Algorithm

DQ7

Toggle

0

0

1

Embedded Program Algorithm

0

Toggle

0

1

Toggle

Erase Suspended

Mode

Erase Suspended Read

(Erase Suspended Sector)

110

1

Toggle

(Note 1)

Erase Suspended Read

(Non-Erase Suspended Sector)

Data

Data

Data

Data

Data

Erase Suspended Read

(Non-Erase Suspended Sector)

DQ7

Toggle

(Note 2)

01

1

(Note 3)

Exceeded

Time Limits

Byte Program in Embedded Program Algorithm

DQ7

Toggle

1

0

1

Program/Erase Program in Embedded Program Algorithm

0

Toggle

1

1

N/A

Erase Suspended

Mode

Erase Suspended Read

(non-Erase Suspended Sector)

DQ7

Toggle

1

1

N/A