MBM29F080A-55PF SPANSION [SPANSION], MBM29F080A-55PF Datasheet - Page 18

• Manufacturer Part Number: MBM29F080A-55PF
• Description: FLASH MEMORY CMOS 8M (1M x 8) BIT
• Manufacturer: SPANSION [SPANSION]

DQ
Toggle Bit I
DQ
Exceeded Timing Limits
DQ
Sector Erase Timer
The Data Polling feature is only active during the Embedded Programming Algorithm, Embedded Erase
Algorithm, Erase Suspend, erase-suspend-program mode, or sector erase time-out. (See “Hardware Sequence
Flags Table” in “ FLEXIBLE SECTOR-ERASE ARCHITECTURE”.)
See “AC Waveforms for Data Polling during Embedded Algorithm Operations” in “ TIMING DIAGRAM” for the
Data Polling timing specifications and diagrams.
The MBM29F080A also features the “Toggle Bit I” as a method to indicate to the host system that the embedded
algorithms are in progress or completed.
During an Embedded Program or Erase Algorithm cycle, successive attempts to read (OE toggling) data from
the device at any address will result in DQ
Erase Algorithm cycle is completed, DQ
attempts. During programming, the Toggle Bit I is valid after the rising edge of the fourth WE pulse in the four
write pulse sequence. For chip erase, and sector erase the Toggle Bit I is valid after the rising edge of the sixth
WE pulse in the six write pulse sequence. For Sector Erase, the Toggle Bit I is valid after the last rising edge of
the sector erase WE pulse. The Toggle Bit I is active during the sector erase time out.
In programming, if the sector being written to is protected, the Toggle Bit I will toggle for about 2 s and then
stop toggling without the data having changed. In erase, the device will erase all the selected sectors except for
the ones that are protected. If all selected sectors are protected, the chip will toggle the Toggle Bit I for about
100 s and then drop back into read mode, having changed none of the data.
Either CE or OE toggling will cause the DQ
cause DQ
See “AC Waveforms for Toggle Bit I during Embedded Algorithm Operations” in “ TIMING DIAGRAM” for the
Toggle Bit I timing specifications and diagrams.
DQ
these conditions DQ
cycle was not successfully completed. Data Polling DQ
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 “MBM29F080A User Bus
Operations Table” in “ FLEXIBLE SECTOR-ERASE ARCHITECTURE”.
The DQ
to 0. In this case the device locks out and never completes the Embedded Algorithm operation. Hence, the
system never reads a valid data on DQ
limits, the DQ
incorrectly used. If this occurs, reset the device.
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 I are valid after the initial sector erase
command sequence.
3
6
5
5
will indicate if the program or erase time has exceeded the specified limits (internal pulse count). Under
5
failure condition may also appear if a user tries to program a 1 to a location that is previously programmed
6
to toggle.
5
bit will indicate a “1.” Please note that this is not a device failure condition since the device was
5
will produce a “1”. This is a failure condition which indicates that the program or erase
7
bit and DQ
6
will stop toggling and valid data will be read on the next successive
6
6
toggling between one and zero. Once the Embedded Program or
to toggle. In addition, an Erase Suspend/Resume command will
6
never stops toggling. Once the device has exceeded timing
7
, DQ
6
is the only operating function of the device under
MBM29F080A
-55/-70/-90
3
will
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