MBM29DL32TF Fujitsu, MBM29DL32TF Datasheet - Page 38

• Manufacturer Part Number: MBM29DL32TF
• Description: 32M-Bit Dual Operation Flash Memory
• Manufacturer: Fujitsu

16. DQ
Exceeded Timing Limits
17. DQ
Sector Erase Timer
18. DQ
Toggle Bit II
19. Reading Toggle Bits DQ
See “7. Toggle Bit I during Embedded Algorithm Operation Timing Diagram” in
Toggle Bit I timing specifications and diagrams.
DQ
these conditions DQ
cycle was not successfully completed. Data Polling is the only operating function of the devices under this
condition. The CE circuit will partially power down the device under these conditions (to approximately 2 mA) .
The OE and WE pins will control the output disable functions as described in “MBM29DL32TF/BF User Bus
Operations Tables (BYTE = V
The DQ
case the devices lock out and never complete the Embedded Algorithm operation. Hence the system never
reads a valid data on DQ
DQ
used. If this occurs, reset the device with command sequence.
After the completion of the initial sector erase command sequence the sector erase time-out will begin. DQ
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
be used to determine if the sector erase timer window is still open. If DQ
erase cycle has begun. If DQ
the command has been accepted, the system software should check the status of DQ
each subsequent Sector Erase command. If DQ
have been accepted.
See “Hardware Sequence Flags Table”.
This toggle bit II, along with DQ
Algorithm or in Erase Suspend.
Successive reads from the erasing sector will cause DQ
devices are in the erase-suspended-read mode, successive reads from the erase-suspended sector will cause
DQ
address of the non-erase 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
mode, DQ
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
However, after the initial two read cycles, if the system determines that the toggle bit is still toggling, the system
5
5
2
6
2
bit will indicate a “1.” Please note that this is not a device failure condition since the devices were incorrectly
will indicate if the program or erase time has exceeded the specified limits (internal pulse count) . Under
to toggle. When the devices are in the erase-suspended-program mode, successive reads from the byte
5
3
2
is different from DQ
toggles while DQ
5
failure condition may also appear if a user tries to program a non blank location without erasing. In this
2
toggles if this bit is read from an erasing sector.
2
2
and DQ
can also be used to determine which sector is being erased. When the device is in the erase
5
6
will produce a “1”. This is a failure condition which indicates that the program or erase
7
does not.) See also “Toggle Bit Status Table” and “9. DQ
to DQ
7
2
6
bit and DQ
in that DQ
can be used together to determine if the erase-suspend-read mode is in progress.
3
IH
6
0
/DQ
is low (“0”) , the device will accept additional sector erase commands. To insure
on the following read cycle.
and BYTE = V
6
, can be used to determine whether the devices are in the Embedded Erase
2
6
6
never stops toggling. Once the devices have exceeded timing limits, the
toggles only when the standard program or Erase, or Erase Suspend
IL
)” ( DEVICE BUS OPERATION).
3
were high on the second status check, the command may not
2
to toggle during the Embedded Erase Algorithm. If the
MBM29DL32TF/BF
3
is high (“1”) the internally controlled
2
2
vs. DQ
bit.
7
to DQ
TIMING DIAGRAM for the
6
” in TIMING DIAGRAM.
0
3
at least twice in a row
prior to and following
7
, is summarized
3
3
may
-70
will
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