Define union that can access bits, nibbles, bytes

Question

union bits {
   unsigned int a : 1;
    unsigned int b : 2;
    unsigned int c : 3;
    unsigned int d : 4;``
    unsigned char x[2];
    unsigned int z; 
};
         


        

Answer 1

you can use bitfields in a struct like the following:

typedef union
{
  struct
  {
    unsigned char bit0 : 1;
    unsigned char bit1 : 1;
    unsigned char bit2 : 1;
    unsigned char bit3 : 1;
    unsigned char bit4 : 1;
    unsigned char bit5 : 1;
    unsigned char bit6 : 1;
    unsigned char bit7 : 1;
  }bits;
  unsigned char byte;
}byte;

and then if you'll have byte b;, you can access each bit like that: b.bits.bit1