RE: [avr-gcc-list] inline'ing sbi/cbi...

[Dave Hansen]

From: Herb Peyerl <address@hidden>
[...]
> I/O port usage.  To make the code readable, I was hoping to do something
> like:
>
>         // from sfr_defs.h
>         #define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
>         #define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
>
>         #define FOO (PORTB,4)
>         sbi(FOO);
>         cbi(FOO);
>
> Obviously I can't do that.  So to work around that, I did:

Why "obviously?"  Because of the preprocessor?  If so, try something like 
this:

  #define Do_The_Work(p, m) p |= m
  #define Turn_On(pm)       Do_The_Work(pm)
  #define MY_BIT            PORTB, 0x04

  unsigned char PORTB;  /* Dummy to allow compile */

  void try_it()
  {
     Turn_On(MY_BIT);  /* preprocessor produces "PORTB |= 0x04;" */
  }

I'm fairly sure you can adapt this to your needs.

Nearly all problems in Computer Science can be solved by an additional level 
of indirection.  ;-)

Regards,
  -=Dave

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