/*H**************************************************************************
* $RCSfile: mcu.h,v $
*****************************************************************************/

#ifndef MCU_H
#define MCU_H

/*==========================*/
/* Predefined SFR Addresses */
/*==========================*/

/******************************************************************************/
#if defined(__ICCAVR__) || defined(__IAR_SYSTEMS_ASM__)
/******************************************************************************/
SFR_B(PINA,   0x00) /* Input Pins, Port A */
SFR_B(DDRA,   0x01) /* Data Direction Register, Port A */
SFR_B(PORTA,  0x02) /* Data Register, Port A */

.......

#define PINA    (*(volatile unsigned char *)0x20)  /* Input Pins, Port A */
#define DDRA    (*(volatile unsigned char *)0x21) /* Data Direction Register, Port A */
#define PORTA   (*(volatile unsigned char *)0x22) /* Data Register, Port A */

..........

/*==========================*/
/* Bit Position Definitions */
/*==========================*/
/* PINA : Input Pins, Port A */
#define    PINA7    7
#define    PINA6    6
#define    PINA5    5
#define    PINA4    4
#define    PINA3    3
#define    PINA2    2
#define    PINA1    1
#define    PINA0    0

/* DDRA : Data Direction Register, Port A */
#define    DDA7     7
#define    DDA6     6
#define    DDA5     5
#define    DDA4     4
#define    DDA3     3
#define    DDA2     2
#define    DDA1     1
#define    DDA0     0

/* PORTA : Data Register, Port A */
#define    PORTA7   7
#define    PORTA6   6
#define    PORTA5   5
#define    PORTA4   4
#define    PORTA3   3
#define    PORTA2   2
#define    PORTA1   1
#define    PORTA0   0

#define Bit(n) (1 << (n))
....
PORTB |= Bit(PINA7);       // set bit
PORTB &= ~ Bit(PINA7);   // clear bit