chap1.c

摩托罗拉Mc6811利程

// Chapter 1 6811 C programs
// Jonathan W. Valvano
// This software accompanies the book,
// Embedded Microcomputer Systems: Real Time Interfacing
// published by Brooks Cole, 1999

// Program 1.12. C definitions of some of the MC68HC11 I/O ports.
#define PORTA *(unsigned char volatile *)(0x1000)
#define PACTL *(unsigned char volatile *)(0x1026)
#define PORTB *(unsigned char volatile *)(0x1004) 
#define PORTC *(unsigned char volatile *)(0x1003)
#define DDRC  *(unsigned char volatile *)(0x1007)
#define PORTD *(unsigned char volatile *)(0x1008)
#define DDRD  *(unsigned char volatile *)(0x1009)
#define PORTE *(unsigned char volatile *)(0x100A)
#define PIOC  *(unsigned char volatile *)(0x1002)
#define TCNT *(unsigned short volatile *)(0x100E)


// Program 1.15. C software that reads from port A and writes to port B.
// Program to implement a NOT gate
// Port A are the 8 digital inputs and Port B are the 8 digital outputs
// Software continuously repeats the following
// 1) Read value from Port A
// 2) Calculate the logical complement
// 3) Write the result out to Port B
#include "HC11.H"
void main(void){ unsigned char data;
  while(1){
    data = PORTA;   // Read from Port A 
    data = ~data;   // Logical complement
    PORTB = data;   // Write from to Port B
}}

// Program 1.17. C software that initializes an I/O port to input.
// MC68HC11A8
    DDRC=0x00;

// Program 1.19. C software that reads from an I/O port input.
// MC68HC11A8
    Happiness=PORTC;

// Program 1.21. C software that initializes an I/O port to output.
// MC68HC11A8
    DDRC=0x0F;

// Program 1.23. C software that outputs an I/O port output.
// MC68HC11A8
    PORTC=0xFF;

// Program 1.25. C functions that provide initialization, 
//        read and write access an I/O port.
// MC68HC11A8
void Init(unsigned char value){
    DDRC=value;}
void Set(unsigned char value){
    PORTC=value;}
unsigned char Read(void){
    return(PORTC);}

// Program 1.28. C programs that implement the 4 bit NOT gate.
// HC05C4, HC708XL36, HC11A8, HC812A4
void init(void){
    DDRC=0xF0;} // PC7-PC4 are outputs, PC3-PC0 are inputs
void main(void){ unsigned char data;
    init();     // call ritual once
    while(1){
       data=PORTC;      // input
       data=(~data)<<4; // complement and shift
       PORTC=data;}}    // output