Clear bit at poistion n in an `int` variable

Clearing a bit

Recall: clear bit

Bit position: 6543210 Starting bit pattern: ..............x............... Bit mask: 111111111111110111111111111111 ----------------------------------------- AND ..............0............... (Bit dnoted by . will remain unchaned)

Making the bit mask

The bit mask 111111111111110111111111111111.... is the complement (negation) of 00000000000000100000000000000.....

The bit mask 111111111111110111111111111111... canbe made with the following operation:

i positions <--------------> 1 << i = 000000..1000000000000000 ~(1 << i) = 111111..0111111111111111

C statement to clear bit position i in an int variable

C code:

int x; int i; x = x & ~(1 << i ); // Clear bit position i in x

Macro definition for the clrbit operation
- C macro to clear the bit at position i in a variable x:

Clear bit at poistion n in an int variable

Clear bit at poistion n in an `int` variable