Hi.

I've got to program a flash 28F512 connected to an 89C51. The uC should recieve a 64Kbyte file via RS232 line and fill the flash with this data in serial ISR. As you know the flash must be erased prior to write and the erasure takes some milliseconds so erasing the entire flash upon receiving the very first byte from PC seems not to be the feasible approach because of lack of time unless the baud rate is reduced to say 300 or so. The byte write operation time is of order of microseconds so programming a blank flash should not have any timing restrictions. All I could decide was to send a string to the uC to have it erase the flash and then after a while send the main 64Kbyte file to be written to the flash, but it looks rather brute force. On the other hand nice NVRAMs are not found here and EEPROMs like 28C512 suffer from a too slow programming time.

Best.