AM29F002 Advanced Micro Devices, AM29F002 Datasheet - Page 13

• Manufacturer Part Number: AM29F002
• Description: 2 Megabit (256 K x 8-Bit) CMOS 5.0 Volt-only Boot Sector Flash Memory
• Manufacturer: Advanced Micro Devices

commands can be assumed to be less than 50 s, the
system need not monitor DQ3. Any command other
than Sector Erase or Erase Suspend during the
time-out period resets the device to reading array
data. The system must rewrite the command sequence
and any additional sector addresses and commands.
The system can monitor DQ3 to determine if the sector
erase timer has timed out. (See the “DQ3: Sector Erase
Timer” section.) The time-out begins from the rising
edge of the final WE# pulse in the command sequence.
Once the sector erase operation has begun, only the
Erase Suspend command is valid. All other commands
are ignored. On the Am29F002 only, note that a hard-
ware reset during the sector erase operation immedi-
ately terminates the operation. The Sector Erase
command sequence should be reinitiated once the de-
vice has returned to reading array data, to ensure data
integrity.
When the Embedded Erase algorithm is complete, the
device returns to reading array data and addresses are
no longer latched. The system can determine the sta-
tus of the erase operation by using DQ7, DQ6, or DQ2.
Refer to “Write Operation Status” for information on
these status bits.
Figure 3 illustrates the algorithm for the erase opera-
tion. Refer to the Erase/Program Operations tables in
the “AC Characteristics” section for parameters, and to
the Sector Erase Operations Timing diagram for timing
waveforms.
Am29F002/Am29F002N
P R E L I M I N A R Y
Notes:
1. See the appropriate Command Definitions table for erase
2. See “DQ3: Sector Erase Timer” for more information.
command sequence.
No
Figure 3. Erase Operation
Command Sequence
Erasure Completed
Write Erase
from System
Data = FFh?
Data Poll
START
Yes
Embedded
Erase
algorithm
in progress
20818C-6
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