2005-03-07 04:49 AM
flash memory: data polling, data toggle ?
2011-05-17 03:06 AM
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