PIC Microcontroller Bit Math Methods

• Copy aligned bits from one register to another
• Copy unaligned bits from one register to another:
• Transfer one bit from a file register to one pin of PORT w/o jitter
• Converting a 3-bit number to a 8-bit mask
• Parity
• Reverse bit order in a byte
• Setting bit number X
• Which bit number was set?
• Testing bits in W
• Clear W, Set bits
• Rotate without carry
• Rotate the nibbles within a byte.
• swap w and f without a temp register

#define BIT(addr,bit) bit
#define ADDR(addr,bit) addr
#define MASK(addr,bit) 1<<(bit)

Then:

#define myflag somereg,5

	movlw BIT(myflag)	
	movf ADDR(myflag),w	
	andlw MASK(myflag)	

	etc...

see also:

• http://www.infosite.com/%7Ejkeyzer/piclist/2000/Jun/1245.html restricting the range of FSR by bit skip and clear/set

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