![](http://datasheet.mmic.net.cn/330000/MBM29LV800B_datasheet_16439274/MBM29LV800B_23.png)
23
MBM29LV800T
-10/-12
/MBM29LV800B
-10/-12
DQ
3
Sector Erase Timer
After the completion of the initial sector erase command sequence the sector erase time-out will begin. DQ
3
will
remain low until the time-out is complete. Data Polling and Toggle Bit are valid after the initial sector erase
command sequence.
If Data Polling or the Toggle Bit I indicates the device has been written with a valid erase command, DQ
3
may
be used to determine if the sector erase timer window is still open. If DQ
3
is high (“1”) the internally controlled
erase cycle has begun; attempts to write subsequent commands to the device will be ignored until the erase
operation is completed as indicated by Data Polling or Toggle Bit I. If DQ
3
is low (“0”), the device will accept
additional sector erase commands. To insure the command has been accepted, the system software should
check the status of DQ
3
prior to and following each subsequent Sector Erase command. If DQ
3
were high on
the second status check, the command may not have been accepted.
Refer to Table 8: Hardware Sequence Flags.
DQ
2
Toggle Bit II
This toggle bit II, along with DQ
6
, can be used to determine whether the devices are in the Embedded Erase
Algorithm or in Erase Suspend.
Successive reads from the erasing sector will cause DQ
2
to toggle during the Embedded Erase Algorithm. If the
devices are in the erase-suspended-read mode, successive reads from the erase-suspended sector will cause
DQ
2
to toggle. When the devices are in the erase-suspended-program mode, successive reads from the byte
address of the non-erase suspended sector will indicate a logic “1” at the DQ
2
bit.
DQ
6
is different from DQ
2
in that DQ
6
toggles only when the standard program or Erase, or Erase Suspend
Program operation is in progress. The behavior of these two status bits, along with that of DQ
7
, is summarized
as follows:
Notes:
1. These status flags apply when outputs are read from a sector that has been erase-suspended.
2. These status flags apply when outputs are read from the byte address of the non-erase suspended sector.
For example, DQ
2
and DQ
6
can be used together to determine the erase-suspend-read mode (DQ
2
toggles while
DQ
6
does not). See also Table 8 and Figure 17.
Furthermore, DQ
2
can also be used to determine which sector is being erased. When the devices are in the
erase mode, DQ
2
toggles if this bit is read from the erasing sector.
Mode
DQ
7
DQ
6
DQ
2
Program
toggles
1
Erase
0
toggles
toggles
Erase Suspend Read
(Erase-Suspended Sector)
(Note 1)
1
1
toggles
Erase Suspend Program
toggles
1 (Note 2)
DQ
7
DQ
7
(Note 2)