A29L040A-70 AMICC [AMIC Technology], A29L040A-70 Datasheet - Page 9

• Manufacturer Part Number: A29L040A-70
• Description: 512K X 8 Bit CMOS 3.0 Volt-only, Uniform Sector Flash Memory
• Manufacturer: AMICC [AMIC Technology]

Chip Erase Command Sequence
Chip erase is a six-bus-cycle operation. The chip erase
command sequence is initiated by writing two unlock cycles,
followed by a set-up command. Two additional unlock write
cycles are then followed by the chip erase command, which
in turn invokes the Embedded Erase algorithm. The device
does not require the system to preprogram prior to erase.
The Embedded Erase algorithm automatically preprograms
and verifies the entire memory for an all zero data pattern
prior to electrical erase. The system is not required to provide
any controls or timings during these operations. The
Command Definitions table shows the address and data
requirements for the chip erase command sequence.
Any commands written to the chip during the Embedded
Erase algorithm are ignored. The system can determine the
status of the erase operation by using I/O
"Write Operation Status" for information on these status bits.
When the Embedded Erase algorithm is complete, the device
returns to reading array data and addresses are no longer
latched.
PRELIMINARY (March, 2005, Version 0.0)
Note : See the appropriate Command Definitions table for
Increment Address
program command sequence.
algorithm in
Embedded
Program
progress
Figure 1. Program Operation
Last Address ?
Write Program
Programming
Verify Data ?
from System
Completed
Command
Sequence
Data Poll
START
Yes
Yes
7
, I/O
6
, or I/O
No
2
. See
8
Figure 2 illustrates the algorithm for the erase operation. See
the Erase/Program Operations tables in "AC Characteristics"
for parameters, and to the Chip/Sector Erase Operation
Timings for timing waveforms.
Sector Erase Command Sequence
Sector erase is a six-bus-cycle operation. The sector erase
command sequence is initiated by writing two unlock cycles,
followed by a set-up command. Two additional unlock write
cycles are then followed by the address of the sector to be
erased, and the sector erase command. The Command
Definitions table shows the address and data requirements
for the sector erase command sequence.
The device does not require the system to preprogram the
memory prior to erase. The Embedded Erase algorithm
automatically programs and verifies the sector for an all zero
data pattern prior to electrical erase. The system is not
required to provide any controls or timings during these
operations.
After the command sequence is written, a sector erase time-
out of 50µs begins. During the time-out period, additional
sector addresses and sector erase commands may be
written. Loading the sector erase buffer may be done in any
sequence, and the number of sectors may be from one
sector to all sectors. The time between these additional
cycles must be less than 50µs, otherwise the last address
and command might not be accepted, and erasure may
begin. It is recommended that processor interrupts be
disabled during this time to ensure all commands are
accepted. The interrupts can be re-enabled after the last
Sector Erase command is written. If the time between
additional sector erase commands can be assumed to be
less than 50µs, the system need not monitor I/O
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 I/O
timer has timed out. (See the " I/O
section.) The time-out begins from the rising edge of the final
Once the sector erase operation has begun, only the Erase
Suspend command is valid. All other commands are ignored.
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 status of the erase
operation by using I/O
Operation Status" for information on these status bits.
Figure 2 illustrates the algorithm for the erase operation.
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.
WE
pulse in the command sequence.
7
, I/O
AMIC Technology, Corp.
3
to determine if the sector erase
6
, or I/O
A29L040A Series
3
: Sector Erase Timer"
2
. Refer to "Write
3
. Any