AVR-Chat

On Mon, 31 Jan 2005 12:13:18 -0800, Larry Barello <yahoo@barello.net>  
wrote:

>
> This is easy to do and produces optimal code on GCC (e.g. sbi/cbi when
> appropriate):
> typedef union// Delclare a union that allows bit & byte access
> {
> unsigned char byte;// This is a byte for 8 bit access
> struct
> {
> unsigned char P0:1;// These are bit-fields
> unsigned char P1:1;
> unsigned char P2:1;
> unsigned char P3:1;
> unsigned char P4:1;
> unsigned char P5:1;
> unsigned char P6:1;
> unsigned char P7:1;// We can use an anonomous struct
> };// because the bit names are unique.
> } sfr_struct;
> #define PORTB (*(sfr_struct *)0x38)// Cast the sram address to the
> structure
> ...
> #define MOTOR_ENABLE_PIN PORTB.P2// Now make an alias for your bit
> ...
> MOTOR_ENABLE_PIN = TRUE;// Now, just use it.
> If you want to access the port as a byte value, then use:
> PORTB.byte = ...


Now that one i like.
Thanks, i will certainly use it.

ST