pwm.rar_c8051f310 PWM

//=================================================================================== //PCA工作在8位脉宽调制器工作方式，在PWM引脚输出一个占空比为0<-->0xfe的PWM //信号且重复输出，可用示波器观察占空比变化。 //实验时短接J12的1,2引脚. //----------------------------------------------------------------------------------- // Includes //----------------------------------------------------------------------------------- #include <c8051f310.h> // SFR declarations #include <INTRINS.H> #include <stdio.h> //------------------------------------------------------------------------------------ //------------------------------------------------------------------------------------ void PORT_Init (void); void PCA_Init (void); void PCA_ISR (void); //------------------------------------------------------------------------------------ // MAIN Routine //------------------------------------------------------------------------------------ void main (void) { unsigned long b; /*关看门狗*/ PCA0MD &= ~0x40; // WDTE = 0 (watchdog timer enable bit) OSCICN |= 0x03; // Set internal oscillator to highest // setting (24500000) PORT_Init (); /*初始化I/O口*/ PCA_Init (); /*PCA初始化成8位脉宽调置方式*/ EIE1= 0x10; EA=1; PCA0CPH0=0x20; while (1) { for(b=0;b>0xffffffff;b++)//延时 { _nop_(); } } } //配置I/O端口 void PORT_Init (void) { P0SKIP =0xff; P1SKIP = 0x3f; XBR1 = 0x42; /*CEX0-->P1.6*/ P1MDOUT |= 0x40; /*使能P0.0脚推挽输出*/ } //配置PCA的CEX0输出8位PWM信号 void PCA_Init (void) { PCA0CN = 0x40; PCA0CPM0 = 0x42; PCA0CPL0 = 0x00; PCA0CPH0 = 0x00; PCA0CPL4 = 0x00; PCA0MD &= 0x40; PCA0MD = 0x01; } //------------------------------- void PCA_ISR (void) interrupt 11 { unsigned char a ; bit PWM_PAC; CF = 0; if(PWM_PAC==0) //占空比由0 >>0xfe { PCA0CPH0=a; a++; if(a==0xfe){PWM_PAC=1;} } else //占空比由0xfe >>0 { PCA0CPH0=a; a--; if(a==0){PWM_PAC=0;} } }