I have to read 8255 port status from f1.c.The variables corresponding to each port is defined using XBYTE in main.c file.What keyword should I use to implement this? Thanks & Regards, Reny.
XBYTE is just a macro - you are effectively using the port address as a "magic number" Possibly a better solution would be to use _at_ - see the Manual. Then it just becomes a standard 'C' definition in one file, and external declarations in a header for the others. There has been plenty of discussion here before on definitions, external declarations and headers - do the search, or see any standard 'C' textbook.
I have to read 8255 Do you work in an antique shop? Erik