chap3.c

摩托罗拉Mc6811利程

// Chapter 3 6811 C programs
// Jonathan W. Valvano
// This software accompanies the book,
// Embedded Microcomputer Systems: Real Time Interfacing
// published by Brooks Cole, 1999

// Program 3.1. A software function that outputs to a simple printer.
void Output(unsigned char LETTER) { unsigned short cnt;
    PORT=LETTER;     /* sets Port outputs */
    Pulse();         /* pulses GO */
    for(cnt=0,cnt<10000,cnt++);   /* Wait for 100 ms */
}  

// Program 3.2. A software function that inputs from an A/D.
unsigned char Input(void); { int dummy;
    Pulse();                  /* pulses GO       */
    dummy=1000;               /* Wait for 5us    */
    return(PORT);             /* Read A/D result */
}  

// Program 3.4. Assembly language routines to initialize and output to a printer.
// MC68HC11A8
void Init(void){
    PIOC=0x00;}
void Out(unsigned char value){
unsigned int n;
    PORTB=value;
    for(n=0;n<28571;n++);}

// Program 3.7. 6811 or 6812 C language routine to create an accurate time delay.
// 6811 or 6812, numCycles can range from 25 to 32767 
void Wait(short numCycles){ 
short EndT;  // TCNT at the end of the delay
    EndT=TCNT+numCycles; 
    while(EndT-(short)TCNT>0);} // wait until TCNT passes EndT

// Program 3.9. C language routines to initialize and read from an A/D.
// MC68HC11A8
void Init(void){
    PIOC=0x01;  // GO=STRB
    DDRC=0;}    // PORTC is data
unsigned char In(void){ int n;
    PORTB=value; // GO pulse
    for(n=0;n<1;n++);
    return(PORTC);}

// Program 3.11. C language routines to initialize and read from a keyboard.
// MC68HC11A8
void Init(void){ 
// PC6-0 is DATA
unsigned char dummy;
    PIOC=0x02;   // EGA=1
    DDRC=0x80;   // STRA=STROBE  
    PORTC=0x00;  // PC7=0  
    dummy=PIOC;  dummy=PORTCL;}
unsigned char In(void){ 
    while ((PIOC & STAF) == 0);
    return(PORTCL); }

// Program 3.13. C language routines to initialize and read from an A/D.
// MC68HC11A8
void Init(void){ 
// PortC=DATA STRA=DONE STRB=GO
unsigned char dummy;
    PIOC=0x03;   // EGA=1 INVB=1
    DDRC=0x00;   // PC inputs  
    dummy=PIOC;  
    dummy=PORTCL;} // clear STAF
unsigned char In(void){
    PORTB=0;   // GO pulse 
    while ((PIOC & STAF) == 0);
    return(PORTCL); }

// Program 3.16. Handshaking C language routines to initialize and read from a sensor.
// MC68HC11A8
void Init(void){ 
// PortC=DATA STRA=READY STRB=ACK
unsigned char dummy;
    PIOC=0x13;   // EGA=1 INVB=1
    DDRC=0x00;   // PC inputs  
    dummy=PIOC;  
    dummy=PORTCL;} // clear STAF

unsigned char In(void){
    while ((PIOC & STAF) == 0);
    return(PORTCL); }

// Program 3.18. Handshaking C language routines to initialize and write to a printer.
// MC68HC11A8
void Init(void){ 
// PortC=DATA STRA=READY STRB=START
    PIOC=0x1E;   // output handshake
    DDRC=0xFF;}  // PC outputs  
void Out(unsigned char data){
    PORTCL=data;
    while ((PIOC & STAF) == 0);}

// Program 3.20. C language initialization of the DS1620
// MC68HC11A8
void Init(void){ // PD5=RST=0
    DDRD=0x38;   // PD4=CLK=1
    PORTD=0x18;} // PD3=DQ=1

// Program 3.22. C language helper functions for the DS1620
// MC68HC11A8
void out8(char code){ int n;
  for(n=0;n<8;n++){
     PORTD &= 0xEF;   // PD4=CLK=0
     if(code&0x01)  
       PORTD |= 0x08; // PD3=DQ=1
     else
       PORTD &= 0xF7; // PD3=DQ=0
     PORTD |= 0x10;   // PD4=CLK=1
     code = code>>1;}}
void start(void){
   PORTD |= 0x20;   // PD5=RST=1
   out8(0xEE);
   PORTD &= 0xDF;}  // PD5=RST=0
void stop(void){
   PORTD |= 0x20;   // PD5=RST=1
   out8(0x22);
   PORTD &= 0xDF;}  // PD5=RST=0

// Program 3.24. C language functions to set the configuration register on the DS1620
// MC68HC11A8
void config(char data){
   PORTD |= 0x20;   // PD5=RST=1
   out8(0x0C);
   out8(data);
   PORTD &= 0xDF;}  // PD5=RST=0

// Program 3.27. C language functions to set the threshold registers on the DS1620
// MC68HC11A8
void out9(int code){ int n;
  for(n=0;n<9;n++){
     PORTD &= 0xEF;   // PD4=CLK=0
     if(code&0x01)  
       PORTD |= 0x08; // PD3=DQ=1
     else
       PORTD &= 0xF7; // PD3=DQ=0
     PORTD |= 0x10;   // PD4=CLK=1
     code = code>>1;}}
void WriteTH(int data){
   PORTD |= 0x20;   // PD5=RST=1
   out8(0x01);
   out9(data);
   PORTD &= 0xDF;}  // PD5=RST=0
void WriteTL(int data){
   PORTD |= 0x20;   // PD5=RST=1
   out8(0x02);
   out9(data);
   PORTD &= 0xDF;}  // PD5=RST=0

// Program 3.29. C language functions to read the configuration register on the DS1620
// MC68HC11A8
unsigned char in8(void){ int n; 
unsigned char result;
  DDRD &= 0xF7; // PD3=DQ input
  for(n=0;n<8;n++){
     PORTD &= 0xEF;   // PD4=CLK=0
     result = result>>1;
     if(PORTD&0x08)  
       result |= 0x80; // PD3=DQ=1
     PORTD |= 0x10;}  // PD4=CLK=1
   DDRD |= 0x08; // PD3=DQ output
   return result;}
unsigned char ReadConfig(void){
unsigned char value;
   PORTD |= 0x20;   // PD5=RST=1
   out8(0xAC);
   value=in8();
   PORTD &= 0xDF;   // PD5=RST=0
   return value;}

// Program 3.31. C language 9-bit read helper function for the DS1620
// MC68HC11A8
unsigned int in9(void){ int n; 
unsigned int result=0;
  DDRD &= 0xF7; // PD3=DQ input
  for(n=0;n<9;n++){
     PORTD &= 0xEF;   // PD4=CLK=0
     result = result>>1;
     if(PORTD&0x08)  
       result |= 0x0100; // PD3=DQ=1
     PORTD |= 0x10;}  // PD4=CLK=1
   DDRD |= 0x08; // PD3=DQ output
   return result;}

// Program 3.32. C language functions to read the temperatures from the DS1620
// MC68HC11A8
unsigned int ReadTH(void){
unsigned int value;
   PORTD |= 0x20;   // PD5=RST=1
   out8(0xA1);
   value=in9();
   PORTD &= 0xDF;   // PD5=RST=0
   return value;}
unsigned int ReadTL(void){
unsigned int value;
   PORTD |= 0x20;   // PD5=RST=1
   out8(0xA2);
   value=in9();
   PORTD &= 0xDF;   // PD5=RST=0
   return value;}
unsigned int ReadT(void){
unsigned int value;
   PORTD |= 0x20;   // PD5=RST=1
   out8(0xAA);
   value=in9();
   PORTD &= 0xDF;   // PD5=RST=0
   return value;}