S29AL004D SPANSION, S29AL004D Datasheet - Page 25

• Manufacturer Part Number: S29AL004D
• Description: 4 Megabit (512 Kx 8-Bit/256 K x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
• Manufacturer: SPANSION

A d v a n c e
I n f o r m a t i o n
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 20 µs 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 is 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 pro-
duces 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
Write Operation Status‚ on page 26
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 DQ7 or DQ6 status bits, just as in
the standard program operation. See
Write Operation Status‚ on page 26
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 Com-
mand Sequence‚ on page 19
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.
February 18, 2005 S29AL004D_00_A1
S29AL004D
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