Hi Experts;

I'm hacking away on a 8051 family processor using the Intel PLM51 compiler. Not knowing PLM very well I'm trying to write to 2 external i/o cards with located at the addresses below. Each card has 3 bytes of i/o - ports a,b, and c. Being a lazy C programmer this is how I did ...

declare c4port_a byte at(0c200h) auxiliary;
declare c4port_a byte at(0c300h) auxiliary;

set_output: procedure(ptr, mask, state);
declare ptr word, mask byte, state byte;
declare valve based ptr byte;

if state > 0 then
valve = (valve or mask);
else
valve = (valve and not mask);

return;
end;

write_output: procedure (index, state) public;
declare index byte;
declare state byte;

declare port byte;
declare shift byte;
declare bitmask byte; /* bits 0-7 */
declare valveaddr word;

/* calculate the port offset from index TBD
0...7: c4port_a byte 0 offset
8...15: c4port_b byte 1 offset
16...23: c4port_c byte 2 offset

24...31: c5port_a byte 3 offset
32...39: c5port_b byte 4 offset
40...47: c5port_c byte 5 offset
*/

port = 0;
shift = 0;

port = index / 8;

/* calculate the outputs bitmask 0-7 */
bitmask = 1;
shift = index MOD 8;
if (shift > 0) then
bitmask = SHL(bitmask, shift);

/* addressing based from cards address */
if (port < 3) then
valveaddr = .c4port_a + port;
else
valveaddr = .c5port_a + (port MOD 3);

/* set the valve */
call set_output(valveaddr, bitmask, state);

return;

end;

What's wrong with my call to set_output?

Thanks;

Wil;