#if...#endif的用法总结

  1 /*******************************************************/
  2 /*                      pwm音阶程序                      */
  3 /*******************************************************/
  4 
  5 
  6 #include <hidef.h>      /* common defines and macros */
  7 #include "derivative.h"      /* derivative-specific definitions */
  8 
  9 #define LEDCPU PORTK_PK4
 10 #define LEDCPU_dir DDRK_DDRK4    //
 11 #define   BUS_CLOCK   32000000
 12 #define   OSC_CLOCK   16000000
 13 
 14 
 15 unsigned int sounghigh[10]={
 16 4048,3816,3402,3030,2866,2551,2273,2024,1912,1704
 17 };
 18 
 19 unsigned int soundtone[8]={
 20 1,2,3,4,5,6,7,8
 21 };
 22 
 23 unsigned int soundlong[8]={
 24 1,1,1,1,1,1,1,1
 25 };
 26 
 27 unsigned int t;
 28 
 29 
 30 /*******************************************************/
 31 /*                       初始化锁相环                       */
 32 /*******************************************************/
 33  void INIT_PLL(void) {
 34     CLKSEL &= 0x7f;
 35     PLLCTL &= 0x8f;
 36     CRGINT &= 0xdf;
 37     
 38     #if(BUS_CLOCK == 40000000)
 39       SYNR = 0x44;
 40     #elif(BUS_CLOCK == 32000000)
 41       SYNR = 0x43;
 42     #elif(BUS_CLOCK == 24000000)
 43       SYNR = 0x42;
 44     #endif
 45     
 46     REFDV = 0X81;
 47     PLLCTL |= 0X70;
 48     asm NOP;
 49     asm NOP;
 50     while(!(CRGFLG&0x08));
 51     CLKSEL |= 0x80; 
 52  }
 53  
 54  
 55  /*******************************************************/
 56 /*                       初始化PWM                        */
 57 /*******************************************************/
 58 void init_pwm(void) {
 59     PWMCTL_CON01 = 1;
 60     PWMPOL_PPOL1 = 1;
 61     PWMPRCLK = 0X55;
 62     PWMCLK = 0X00;
 63     PWMPER01 = 3816;
 64     PWME_PWME1 = 1;
 65 }       
 66 
 67 /*******************************************************/
 68 /*                      延时函数                      */
 69 /*******************************************************/
 70 void delay(void) {
 71   unsigned int i,j;
 72   for(i=0;i<10;i++)
 73     for(j=0;j<50000;j++);
 74 }
 75 
 76 /*******************************************************/
 77 /*                      延时函数                      */
 78 /*******************************************************/
 79 void delay2(unsigned int n) {
 80   unsigned int i,j,k;
 81   for(k=0;k<n;k++)
 82    for(i=0;i<50;i++)
 83     for(j=0;j<50000;j++);
 84 }
 85 
 86 /*******************************************************/
 87 /*                       主函数                       */
 88 /*******************************************************/
 89 
 90 void main(void) {
 91  DisableInterrupts;
 92  INIT_PLL();
 93  init_pwm();
 94  LEDCPU_dir=1;
 95  LEDCPU=0;
 96  EnableInterrupts;
 97  
 98  for(;;) {
 99   for(t=0;t<8;t++) {
100     PWMPER01=sounghigh[soundtone[t]];
101     PWMDTY01=sounghigh[soundtone[t]]/2;
102     delay2(soundlong[t]);
103     PWMDTY01=0;
104     delay();
105   }        
106   delay2(5);
107   
108   for(t=8;t>0;t--) {
109     PWMPER01=sounghigh[soundtone[t-1]];
110     PWMDTY01=sounghigh[soundtone[t]]/2;
111     delay2(soundlong[t]);
112     PWMDTY01=0;
113     delay();
114   }
115   delay2(5);
116  }                     
117 
118 
119     EnableInterrupts;
120 
121 
122   for(;;) {
123     _FEED_COP(); /* feeds the dog */
124   } /* loop forever */
125 
126 }