D at a
S hee t
10.8
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. This command is valid only during the
sector erase operation, including the 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 typical
of 5
μs (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 device 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 suspends
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
for information on these
status bits.
After an erase-suspended program operation is complete, the device 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 word program operation. Refer to
for more information.
In the erase-suspend-read mode, the system can also issue the autoselect command sequence. Refer to the
and
sections for details.
To resume the sector erase operation, the system must write the Erase Resume command. Further writes of
the Resume command are ignored. Another Erase Suspend command can be written after the chip resumes
erasing.
During an erase operation, this flash device performs multiple internal operations which are invisible to the
system. When an erase operation is suspended, any of the internal operations that were not fully completed
must be restarted. As such, if this flash device is continually issued suspend/resume commands in rapid
succession, erase progress is impeded as a function of the number of suspends. The result is a longer
cumulative erase time than without suspends. Note that the additional suspends do not affect device reliability
or future performance. In most systems rapid erase/suspend activity occurs only briefly. In such cases, erase
performance is not significantly impacted.
50
S29GL-N MirrorBit
®
Flash Family
S29GL-N_01_09 November 16, 2007
SPANSION [ SPANSION ]
