AM29LV640MH SPANSION [SPANSION], AM29LV640MH Datasheet - Page 37

• Manufacturer Part Number: AM29LV640MH
• Description: 64 Megabit (4 M x 16-Bit/8 M x 8-Bit) MirrorBit 3.0 Volt-only Uniform Sector Flash Memory with VersatileI/O Control
• Manufacturer: SPANSION [SPANSION]

WRITE OPERATION STATUS
The device provides several bits to determine the sta-
tus of a program or erase operation: DQ2, DQ3, DQ5,
DQ6, and DQ7.
tions describe the function of these bits. DQ7 and DQ6
each offer a method for determining whether a pro-
gram 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
completed.
DQ7: Data# Polling
The Data# Polling bit, DQ7, indicates to the host sys-
tem whether an Embedded Program or Erase algo-
rithm is in progress or completed, or whether the
device is in Erase Suspend. Data# Polling is valid after
the rising edge of the final WE# pulse in the command
sequence.
During the Embedded Program algorithm, the device
outputs on DQ7 the complement of the datum pro-
grammed to DQ7. This DQ7 status also applies to pro-
g r a m m i n g d u r i n g E r a s e S u s p e n d . W h e n t h e
Embedded Program algorithm is complete, 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 1 µs, then the device returns to the read
mode.
During the Embedded Erase algorithm, Data# Polling
produces a “0” on DQ7. When the Embedded Erase
December 14, 2005
Table 12
and the following subsec-
D A T A S H E E T
Am29LV640MH/L
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 infor-
mation on DQ7.
After an erase command sequence is written, if all
sectors selected for erasing are protected, Data# Poll-
ing on DQ7 is active for approximately 100 µs, 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 se-
lected sectors that are protected. However, if the sys-
tem reads DQ7 at an address within a protected
sector, the status may not be valid.
Just prior to the completion of an Embedded Program
or Erase operation, DQ7 may change asynchronously
with DQ0–DQ6 while Output Enable (OE#) is asserted
low. That is, the 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 com-
pleted the program or erase operation and DQ7 has
valid data, the data outputs on DQ0–DQ6 may be still
invalid. Valid data on DQ0–DQ7 will appear on suc-
cessive read cycles.
Table 12
Figure 8 shows the Data# Polling algorithm. Figure 20
in the
Polling timing diagram.
AC Characteristics
shows the outputs for Data# Polling on DQ7.
section shows the Data#
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