flash memory: data polling, data toggle ?

[rk1]

Posted on March 07, 2005 at 13:49

flash memory: data polling, data toggle ?

[rk1]

Posted on May 17, 2011 at 12:06

hi,

does the flash return to ''READ MODE'' automaticall (i.e. by timeout) after an error occured during writing/erasing the flash ?

or do I have to set it back to ''READ MODE'' manually by using the ''Reset Flash'' instruction cycle ?

if yes: what happens in the following situation:

- the mcu writes/erases a byte in the flash.

- then, the mcu uses ''data polling'' to test when the operation is completed.

- now, i.e. an interrupt-service-routine interrupts the ''data polling''

- the writing/erasing fails, but the mcu doesn't know this yet, because the interrupt-service-routine is still working.

- the ''data polling'' continues much later, when the flash is in ''READ MODE'' again.

- now: DQ7=old_D7, DQ6=old_D6, DQ5=old_D5

assume that old_D7 = !D7. then the ''data-polling-algorithm'' (as shown on the ''Data Polling Flowchart in the datasheet) results in an infinite loop (because DQ7=!D7, and DQ5=0).

right ?

by the way, the ''data-toggle-algorithm'' works also in this case.

thanks