The SiLabs parts are pretty cutting-edge, but the 8255 is an old crock that's been obsolete for years!

The only real reason that the 8255 was ever used was for old-fashioned 8031s with external memory - because the address+data bus used up nearly all the port pins.

With an SiLabs C8051F226, you have four free ports - because the chip has internal Flash and SRAM! So why would you want to use an 8255??


So don't waste your time with old crocks like the 8255!