A29040 Series
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.
START
Erase Suspend/Erase Resume Commands
The Erase Suspend command allows the system to interrupt
a sector erase operation and then read data from, or
program data to, any sector not selected for erasure. This
command is valid only during the sector erase operation,
including the 50µs time-out period during the sector erase
command sequence. The Erase Suspend command is
ignored if written during the chip erase operation or
Embedded Program algorithm. Writing the Erase Suspend
command during the Sector Erase time-out immediately
terminates the time-out period and suspends the erase
operation. Addresses are "don't cares" when writing the
Erase Suspend command.
When the Erase Suspend command is written during a
sector erase operation, the device requires a maximum of
20µs to suspend the erase operation. However, when the
Erase Suspend command is written during the sector erase
time-out, the device immediately terminates the time-out
period and suspends the erase operation.
After the erase operation has been suspended, the system
can read array data from or program data to any sector not
selected for erasure. (The device "erase suspends" all
sectors selected for erasure.) Normal read and write timings
and command definitions apply. Reading at any address
within erase-suspended sectors produces status data on
I/O
7
- I/O
0
. The system can use I/O
7
, or I/O
6
and I/O
2
together, to determine if a sector is actively erasing or is
erase-suspended. See "Write Operation Status" for
information on these status bits.
After an erase-suspended program operation is complete,
the system can once again read array data within non-
suspended sectors. The system can determine the status of
the program operation using the I/O
7
or I/O
6
status bits, just
as in the standard program operation. See "Write Operation
Status" for more information.
The system may also write the autoselect command
sequence when the device is in the Erase Suspend mode.
The device allows reading autoselect codes even at
addresses within erasing sectors, since the codes are not
stored in the memory array. When the device exits the
autoselect mode, the device reverts to the Erase Suspend
mode, and is ready for another valid operation. See
"Autoselect Command Sequence" for more information.
The system must write the Erase Resume command
(address bits are "don't care") to exit the erase suspend
mode and continue the sector erase operation. Further
writes of the Resume command are ignored. Another Erase
Suspend command can be written after the device has
resumed erasing.
Write Erase
Command
Sequence
Data Poll
from System
Embedded
Erase
algorithm in
progress
No
Data = FFh ?
Yes
Erasure Completed
Note :
1. See the appropriate Command Definitions table for erase
command sequences.
2. See "I/O
3
: Sector Erase Timer" for more information.
Figure 2. Erase Operation
PRELIMINARY
(August, 2001, Version 0.5)
9
AMIC Technology, Inc.
AMICC [ AMIC TECHNOLOGY ]
