E S I
E S I
Excel Semiconductor inc.
WRITE OPERATION STATUS
Erase algorithm is complete, or if the device enters
the Erase Suspend mode, Data# polling produces a
“1” on DQ7. The system must provide an address
within any of the sectors selected for erasure to read
valid status information on DQ7.
In the ES29LV400 device, several bits are provided
to determine the status of a program or erase oper-
ation: DQ2, DQ3, DQ5, DQ6, DQ7 and RY/BY#.
Table 6 and the following subsections describe the
function of these bits. DQ7 and DQ6 each offer a
method for determining whether a program or erase
operation is complete or in progress. The device
also provides a hardware-based output signal, RY/
BY#, to determine whether an Embedded Program
or Erase operation is in progress or has been com-
pleted.
Erase on the Protected Sectors
After an erase command sequence is written, if all
sectors selected for erasing are protected, Data#
Polling on DQ7 is active for approximately 1.8us,
then the device returns to the read mode. If not all
selected sectors are protected, the Embedded Erase
algorithm erases the unprotected sectors, and
ignores the selected sectors that are protected. How-
ever, if the system reads DQ7 at an address within a
protected sector, the status may not be valid.
DQ7 (DATA# POLLING)
The Data# Polling bit, DQ7, indicates to the host
system whether an Embedded Program or Erase
algorithm is in progress or completed, or whether a
device is in Erase Suspend. Data# Polling is valid
after the rising edge of the final WE# pulse in the
command sequence.
Data# Polling Algorithm
Just prior to the completion of an Embedded
Program or Ease operation, DQ7 may change
asynchronously with DQ0-DQ6 while Output
Enable(OE#) is asserted low. That is, this device
may change from providing status information to
valid data on DQ7. Depending on when the system
samples the DQ7 output, it may read the status or
valid data. Even if the device has completed the
program or erase operation and DQ7 has valid data,
the data outputs on DQ0-DQ7 will appear on
successive read cycles.
During Programming
During the Embedded Program algorithm, the
device outputs on DQ7 the complement of the
datum programmed to DQ7. This DQ7 status also
applies to programming during Erase Suspend.
When the Embedded Program algorithm is com-
plete, the device outputs the datum programmed to
DQ7. The system must provide the program
address to read valid status information on DQ7. If
a program address falls within a protected sector,
Data# Polling on DQ7 is active for approximately
250ns, then the device returns to the read mode.
Table 6 shows the outputs for Data# Polling on DQ7.
Fig. 9 shows the Data# Polling algorithm. Fig. 22 in
the AC Characteristics section shows the Data#
Polling timing diagram.
During Erase
During the Embedded Erase algorithm, Data# Poll-
ing produces a “0” on DQ7. When the Embedded
21
Rev.0B January 5, 2006
ES29LV400E
EXCELSEMI [ EXCEL SEMICONDUCTOR INC. ]
