am42bds6408h Meet Spansion Inc., am42bds6408h Datasheet - Page 38

• Manufacturer Part Number: am42bds6408h
• Description: Cmos 1.8 Volt-only Simultaneous Read/write, Burst Mode Flash Memory, And 8 Mbit 512 K X 16-bit Sram
• Manufacturer: Meet Spansion Inc.

The interrupts can be re-enabled after the last Sector
Erase command is written. Any command other than
Sector Erase or Erase Suspend during the time-out
period resets that bank to the read mode. The system
must rewrite the command sequence and any addi-
tional addresses and commands.
The system can monitor DQ3 to determine if the sector
erase timer has timed out (See
Timer” section on page
the rising edge of the final WE# pulse in the command
sequence.
When the Embedded Erase algorithm is complete, the
bank returns to reading array data and addresses are
no longer latched. Note that while the Embedded Erase
operation is in progress, the system can read data from
the non-erasing bank. The system can determine the
status of the erase operation by reading DQ7 or
DQ6/DQ2 in the erasing bank. Refer to the
Operation Status” section on page 43
on these status bits.
Once the sector erase operation has begun, only the
Erase Suspend command is valid. All other commands
are ignored. However, note that a hardware reset
immediately terminates the erase operation. If that
occurs, the sector erase command sequence should
be reinitiated once that bank has returned to reading
array data, to ensure data integrity.
The host system may also initiate the sector erase
command sequence while the device is in the unlock
bypass mode. The command sequence is four cycles
cycles in length instead of six cycles.
Figure 5, “Erase Operation,” on page 37
algorithm for the erase operation. Refer to the
Erase/Program Operations table in the
Characteristics,” on page 65
diagrams.
Erase Suspend/Erase Resume Commands
The Erase Suspend command, B0h, allows the system
to interrupt a sector erase operation and then read data
from, or program data to, any sector not selected for
erasure. The bank address is required when writing
36
46.) The time-out begins from
for parameters and timing
A D V A N C E
“DQ3: Sector Erase
for information
illustrates the
Figure , “AC
“Write
Am42BDS6408H
I N F O R M A T I O N
this command. This command is valid only during the
sector erase operation, including the minimum 50 µs
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.
When the Erase Suspend command is written during
the 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 immedi-
ately terminates the time-out period and suspends the
erase operation.
After the erase operation has been suspended, the
bank enters the erase-suspend-read mode. The
system can read data from or program data to any
sector not selected for erasure. (The device “erase sus-
pends” all sectors selected for erasure.) Reading at any
address within erase-suspended sectors produces
status information 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. Refer
to the
information on these status bits.
After an erase-suspended program operation is com-
plete, the bank returns to the erase-suspend-read
mode. The system can determine the status of the
program operation using the DQ7 or DQ6 status bits,
just as in the standard program operation. Refer to the
“Write Operation Status” section on page 43
information.
In the erase-suspend-read mode, the system can also
issue the autoselect command sequence. Refer to the
“ A m 4 2 B D S 6 4 0 8 H B o o t S e c t o r / S e c t o r B l o ck
Addresses for Protection/Unprotection” section on
page 16
on page 33
To resume the sector erase operation, the system must
write the Erase Resume command. The bank address
of the erase-suspended bank is required when writing
this command. Further writes of the Resume command
Figure , “Write Operation Status,” on page 43
and
for details.
“Autoselect Command Sequence” section
October 23, 2003
for more
for