Hi All,
I want the 89C51 receive a 64kbyte file from PC, using serial interrupt and write it immediately into a non-volatile memory (like FLASH 28F512).
In the serial ISR, each received byte is written into the 28F512. Everything seems to be okay except that upon receiving the fist byte of data, The 8051 has to erase all the 28F512 -as recommended by manufacturer- and this process takes some 1 second but the ISR does not have such a big amount of time between receiving the first and the second byte. As you probably know, we are supposed to erase the FLASH memories prior to writing to them. On the other hand using EEPROM(28C512) -which needn't be erased prior to write- instead of FLASH(28F512) is not possible since although EEPROMs need not be erased prior to writing, but their write cycle takes some 5 milliseconds which is quite a lot more that microseconds of FLASHs, so baud rates more than 1200 can not be used with EEPROMs.
The question is that how can I erase the FLASH without encountering the time restrictions of serial ISR?
How about sending a dummy preamble to notify the 8051 the start of transmission then a one or 2 seconds delay, and then sending the 64kbyte file?
Best.