A few years back, a fellow at U. Rostock published an app called FPGAFLASH, or something like that, the purpose of which was (a) to boot his FPGA from a conventional FLASH memory, and, (b) by setting a jumper, enable the FLASH to be programmed from a serial port residing in a PC. Of course, this was only possible due to a CPLD (XC9572) that provided the necessary logic. I was never able to find the entire package, i.e. HDL code, schematic, PC source code, to enable me to do this, but, clearly, it's possible with the aid of the extra hardware.

I think it possible that you're looking for the hard way to do this, however, since, if you can access this FLASH memory from an 805x, you have to provide some form of bank switching logic anyway. Further, if yuo want to write it, you have to map it into external data space, which is the only way you can write to it. Data on how, exactly, to write to it is available from the FLASH memory vendor.

Good luck!

RE