Hi :
Take a look at this function
sbit a=P0^1; void manipulate_port() { a=1; Delay(); a=0; Delay(); a=1; Delay(); a=0; }
In above code, the hardware(P0.1) is manipulated in the function manipulate_port(); Now I want to manipulate one of the pins of PORT0 according to different parameter. I can program eight different process with eight different pin manipulation and then select which process to be executed by a parameter. But I donot think it is a properly method. Should I only use one process to complete such goal. Because the manipulation is fixed(no matter which pin is use) So shall I program the process in such way.
sbit a0=P0^1; sbit a1=P0^2; ........ sbit a7=P0^7; void manipulate_port(uchar x) { // according different x, the a will be point to different pin,then execute the following a=1; Delay(); a=0; Delay(); a=1; Delay(); a=0; }
Is this resonable(or is this idea will be supported by keil)? If so ,how can I do it.
Thanks for your replying.
Jason Liu
As already noted, the 8051 doesn't have any means to indirectly address the ports (or any other SFR) - so you can't have a pointer.
You could try passing an "index", and use that to select the appropriate port in a 'switch'...
switch( port_index ) { case port_0: // Do stuff with P0 break; case port_1: // Do stuff with P1 break; : : etc, etc,...
It may well not be worth it - just write specific functions for the specific pins you want to twiddle; maybe with macros...?