MBM29DL640E Fujitsu Microelectronics, Inc., MBM29DL640E Datasheet - Page 35

• Manufacturer Part Number: MBM29DL640E
• Description: Flash Memory 64 M 8 M X 8/4 M X 16 Bit Dual Operation
• Manufacturer: Fujitsu Microelectronics, Inc.

DQ
Exceeded Timing Limits
DQ
Sector Erase Timer
DQ
Toggle Bit II
Reading Toggle Bits DQ
DQ
these conditions DQ
not successfully completed. Data Polling is only operating function of the device under this condition. The CE
circuit will partially power down device under these conditions (to approximately 2 mA) . The OE and WE pins
will control the output disable functions as described in Tables 2 and 3.
The DQ
this case the device locks out and never completes the Embedded Algorithm operation. Hence, the system never
reads valid data on DQ
bit will indicate a “1.” Please note that this is not a device failure condition since the device was incorrectly used.
If this occurs, reset device with the command sequence.
After completion of the initial sector erase command sequence, sector erase time-out begins. DQ
low until the time-out is completed. Data Polling and Toggle Bit are valid after the initial sector erase command
sequence.
If Data Polling or the Toggle Bit I indicates that a valid erase command has been written, DQ
determine whether the sector erase timer window is still open. If DQ
cycle has begun. If DQ
command has been accepted, the system software should check the status of DQ
subsequent Sector Erase command. If DQ
been accepted.
See Table 12 : Hardware Sequence Flags.
This toggle bit II, along with DQ
Algorithm or in Erase Suspend.
Successive reads from the erasing sector will cause DQ
device is in the erase-suspended-read mode, successive reads from the erase-suspended sector will cause
DQ
suspended sector will indicate a logic “1” at the DQ
DQ
Program operation is in progress. The behavior of these two status bits, along with that of DQ
as follows :
For example, DQ
(DQ
Furthermore DQ
if this bit is read from an erasing sector.
To operate toggle bit function properly, CE or OE must be high when bank address is changed.
Whenever the system initially begins reading toggle bit status, it must read DQ
to determine whether a toggle bit is toggling. Typically a system would note and store the value of the toggle bit
after the first read. After the second read, the system would compare the new value of the toggle bit with the
first. If the toggle bit is not toggling, the device has completed the program or erase operation. The system can
read array data on DQ
5
3
2
5
2
6
2
to toggle. When the device is in the erase-suspended-program mode, successive reads from the non-erase
will indicate if the program or erase time has exceeded the specified limits (internal pulse count) . Under
is different from DQ
toggles while DQ
5
failure condition may also appear if a user tries to program a non-blank location without pre-erase. In
2
2
can also be used to determine which sector is being erased. At the erase mode, DQ
and DQ
5
will produce “1”. This is a failure condition indicating that the program or erase cycle was
6
7
6
7
/DQ
3
to DQ
does not.) See also Table 13 and Figure 12.
bit and DQ
is low (“0”) , the device will accept additional sector erase commands. To insure the
2
6
in that DQ
2
can be used together to determine if the erase-suspend-read mode is in progress.
0
on the following read cycle.
6
, can be used to determine whether the device is in the Embedded Erase
6
never stop toggling. Once the device has exceeded timing limits, the DQ
6
toggles only when the standard program or Erase, or Erase Suspend
3
were high on the second status check, the command may not have
2
bit.
2
to toggle during the Embedded Erase Algorithm. If the
MBM29DL640E
3
is high (“1”) the internally controlled erase
7
to DQ
3
prior to and following each
0
at least twice in a row
3
7
, is summarized
may be used to
3
will remain
80/90/12
2
toggles
5
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