Hi there..
It's incredible simple - yet I haven't manage to locate the spot in the documentation to this chip. Alas, I have this code :
sfr p1 = 0x90;
main() {
while(1) { p1 = 0x55; } }
As you can see, it's very simple. But when i measure on the ports, I get
2.0V on all ports - ie. it doesn't seem to do what I tell it to do.Another thing is that apparently, you have to setup the port for reading. Ie. you write 0xff to the port and then you can write what ever you want. I've looked everywhere in the documentation[1] but I simply can't find the place where it tells me that. There simply doesn't seem to be a SFR register anywhere in that chip that controls the input/output state of the ports.
[1] Infineon : User's Manual 08.95 Microcomputer Components SAB 80515/SAB 80C515 8-Bit Single-Chip Microcontroller Family and C500 Architecture and Instruction Set