AM29SL400C SPANSION [SPANSION], AM29SL400C Datasheet - Page 19

• Manufacturer Part Number: AM29SL400C
• Description: 4 Megabit (512 K x 8-Bit/256 K x 16-Bit) CMOS 1.8 Volt-only Super Low Voltage Flash Memory
• Manufacturer: SPANSION [SPANSION]

When the Embedded Erase algorithm is complete,
the device returns to reading array data and ad-
dresses are no longer latched. The system can deter-
mine the status of the erase operation by using DQ7,
DQ6, DQ2, or RY/BY#. (Refer to
Status‚ on page 18
bits.)
Figure 4
tion. Refer to the
page 30
page 32
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 sec-
tor erase operation, including the 50 µs time-out pe-
riod during the sector erase command sequence. The
Erase Suspend command is ignored if written during
the chip erase operation or Embedded Program algo-
rithm. Writing the Erase Suspend command during
the Sector Erase time-out immediately terminates
the time-out period and suspends the erase opera-
tion. 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 maxi-
mum of 20 µs to suspend the erase operation. How-
ever, when the Erase Suspend command is written
during the sector erase time-out, the device immedi-
ately 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 defini-
t i o n s a p p l y. R e a d i n g a t a n y a d d r e s s w i t h i n
erase-suspended sectors produces status data on
DQ7–DQ0. The system can use DQ7, or DQ6 and
DQ2 together, to determine if a sector is actively
erasing or is erase-suspended. See
Status‚ on page 18
bits.
After an erase-suspended program operation is com-
plete, the system can once again read array data
within non-suspended sectors. The system can de-
termine the status of the program operation using
the DQ7 or DQ6 status bits, just as in the standard
March 3, 2005
illustrates the algorithm for the erase opera-
for timing diagrams.
for parameters, and to
Erase/Program Operations‚ on
for information on these status
for information on these status
A d v a n c e
Write Operation
Write Operation
Figure 18‚ on
I n f o r m a t i o n
program operation. See
page 18
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
quence‚ on page 15
The system must write the Erase Resume command
(address bits are “don’t care”) to exit the erase sus-
pend 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.
Notes:
1. See
2. See
formation.
Table 5 on page 18
DQ3: Sector Erase Timer‚ on page 21
for more information.
No
Figure 4. Erase Operation
Command Sequence
Erasure Completed
Write Erase
from System
Data = FFh?
Data Poll
START
for more information.
Yes
Autoselect Command Se-
for erase command sequence.
Write Operation Status‚ on
Embedded
Erase
algorithm
in progress
for more in-
17