PIC Microcontoller Bit Math Method

Toggle or NOT or flip bit number X

Obviously setting, or clearing a bit is done with bsf and bcf. Toggleing a bit is done with XOR and a mask. But what if you don't know which bit to set, clear or toggle before the program is compiled?

From: http://www.myke.com/basic.htm

There are two ways of implementing this operation based on where the input value is relative to the output value. If they are the same (ie the operation is to complement a specific bit), the code to be used is simply:

 movlw  1 << BitNumber         ;  Complement Specific Bit for "NOT"
  xorwf  BitRegister, f

If the bit is in another register, then the value stored is the complement of it:

 bcf    Result                 ;  Assume that the Input Bit is Set
  btfss  Bit                    ;   - If it is Set, then Result Correct
   bsf   Result                 ;  Input Bit Reset, Set the Result

See also:

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