MX26LV004T Macronix, MX26LV004T Datasheet - Page 14

• Manufacturer Part Number: MX26LV004T
• Description: (MX26LV004T/B) 4M-Bit CMOS Single Voltage Flash Memory
• Manufacturer: Macronix

would compare the new value of the toggle bit with the
first. If the toggle bit is not toggling, the device has com-
pleted the program or erase operation. The system can
read array data on Q7-Q0 on the following read cycle.
However, if after the initial two read cycles, the system
determines that the toggle bit is still toggling, the sys-
tem also should note whether the value of Q5 is high
(see the section on Q5). If it is, the system should then
determine again whether the toggle bit is toggling, since
the toggle bit may have stopped toggling just as Q5 went
high. If the toggle bit is no longer toggling, the device
has successfully completed the program or erase op-
eration. If it is still toggling, the device did not complete
the operation successfully, and the system must write
the reset command to return to reading array data.
The remaining scenario is that system initially determines
that the toggle bit is toggling and Q5 has not gone high.
The system may continue to monitor the toggle bit and
Q5 through successive read cycles, determining the sta-
tus as described in the previous paragraph. Alterna-
tively, it may choose to perform other system tasks. In
this case, the system must start at the beginning of the
algorithm when it returns to determine the status of the
operation.
Q5
Exceeded Timing Limits
Q5 will indicate if the program or erase time has ex-
ceeded the specified limits (internal pulse count). Under
these conditions Q5 will produce a "1". This time-out
condition indicates that the program or erase cycle was
not successfully completed. Data Polling and Toggle Bit
are the only operating functions of the device under this
condition.
If this time-out condition occurs during sector erase op-
eration, it specifies that a particular sector is bad and it
may not be reused. However, other sectors are still func-
tional and may be used for the program or erase opera-
tion. The device must be reset to use other sectors.
Write the Reset command sequence to the device, and
then execute program or erase command sequence. This
allows the system to continue to use the other active
sectors in the device.
If this time-out condition occurs during the chip erase
P/N:PM1099
14
operation, it specifies that the entire chip is bad or com-
bination of sectors are bad.
If this time-out condition occurs during the byte program-
ming operation, it specifies that the entire sector con-
taining that byte is bad and this sector maynot be re-
used, (other sectors are still functional and can be re-
used).
The time-out condition will not appear if a user tries to
program a non blank location without erasing. Please
note that this is not a device failure condition since the
device was incorrectly used.
MX26LV004T/B
REV. 0.02, JUL. 12, 2004