EN29F002N Datasheet, PDF (11/32 Pages) List of Unclassifed Manufacturers – 2 Megabit (256K x 8-bit) Flash Memory

EN29F002 / EN29F002N
The flowchart for the Toggle Bit (DQ6) is shown in Flowchart 6. The Toggle Bit timing diagram is
shown in Figure 9.
DQ5
Exceeded Timing Limits
DQ5 will indicate if the program or erase time has exceeded the specified limits (internal pulse
count). Under these conditions DQ5 will produce a “1”. (The Toggle Bit (DQ6) should also be
checked at this time to make sure that the DQ5 is not a “1” due to the device having returned to read
mode.) This is a failure condition which indicates that the program or erase cycle was not
successfully completed. DATA Polling (DQ7), Toggle Bit (DQ6) and Erase Toggle Bit (DQ2) still
function under this condition. Setting the CE to V_IH will partially power down the device under those
conditions. The O E and W E pins will control the output disable functions as described in Table 3.
The DQ5 failure condition will also appear if the user tries to program a “1” to a location that was
previously programmed to a “0”. In this case, the device goes into Hang or Error mode out and never
completes the Embedded Program Algorithm. Hence, the system never reads valid data on DQ7
and DQ6 never stops toggling. Once the device exceeds the timing limits, DQ5 will indicate a “1”.
Please note that this is not a device failure condition since the device was used incorrectly. If timing
limits are exceeded, reset the device. (See Table 6)
DQ3
Sector Erase Command Timeout
This device does not support multiple sector erase commands. DQ3 will go high immediately after
the first 30h command (the sixth write cycle). Any extra 30h commands will be ignored (or taken as a
resume command if erase suspended).
DQ2
Erase Toggle Bit II
In the sector erase operation, DQ2 will toggle with OE or CE when a read is attempted within the
sector that is being erased. DQ2 will not toggle if the read address is not within the sector that is
selected to be erased. In the chip erase operation, however, DQ2 will toggle with OE or CE
regardless of the address given by the user. This is because all sectors are to be erased. (See Table
6)
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