#include "STM8S103F3U.h"

//自定义的布尔类型233
typedef enum _bool{false = 0,true}bool;
 
//同步方波电平
_Bool Pin_Sync @PB_ODR:4;

//PWM占空比更新周期
unsigned char period=0;
//当前PWM出来的占空比
unsigned char duty_cycle=0;

//正弦表
unsigned char pwm[159]={5,10,15,20,25,30,35,40,45,50,54,59,
64,69,74,79,84,88,93,98,102,107,111,116,120,125,129,133,138,
142,146,150,154,158,162,166,170,173,177,181,184,188,191,194,
198,201,204,207,210,212,215,218,220,223,225,228,230,232,234,
236,238,239,241,243,244,245,247,248,249,250,251,252,252,253,
253,254,254,254,254,254,254,254,254,253,253,252,252,251,250,
249,248,247,245,244,243,241,239,238,236,234,232,230,228,225,
223,220,218,215,212,210,207,204,201,198,194,191,188,184,181,
177,173,170,166,162,158,154,150,146,142,138,133,129,125,120,
116,111,107,102,98,93,88,84,79,74,69,64,59,54,50,45,40,35,30
,25,20,15,10,5,0};


//延时函数 貌似没用 不过留着
void DelayMS(unsigned int ms)
{
	unsigned char i;
	while(ms != 0)
	{
		for(i=0;i<250;i++);
		for(i=0;i<75;i++);
		ms--;
	}
}

//TIM4的初始化
void Init_50Hz(void){
	TIM4_IER = 0x00; // 禁止中断
	TIM4_EGR = 0x01; // 允许产生更新事件
	
	TIM4_PSCR = 0x02; // 2^2=4分频
	TIM4_ARR = 0xF7; // 设定重装载时的寄存器值,最大值FF
	TIM4_CNTR = 0xF7; // 设定计数器的初值
	
	TIM4_CR1 = 0x01; // b0 = 1,允许计数器工作
	TIM4_IER = 0x01; // 允许更新中断
}

//TIM2的初始化 用于PWM发生
void Init_PWM(void){
	// CC1P = CC2P = 1，高电平为有效电平
	// CC1E = CC2E = 1，开启输出引脚	
	TIM2_CCER1 =  0x33;

	// 通道1,2 被设置成比较输出方式
	// OC2M = 111,为PWM 模式2，
	// 向上计数时，若计数器小于比较值，为无效电平
	// 即当计数器在0 到比较值时，输出为1，否则为0	
	TIM2_CCMR1 = 0x70;
	TIM2_CCMR2 = 0x70;


	//设定频率-----------------------------
	//2^1=2分频
	TIM2_PSCR = 0x01;	
	//初始化自动装载寄存器 
	//Fpwm=fMaster/TIM2_PSCR/TIM2_ARR
	//=16000KHz/0xFF/(2^0x01)=31.25KHz
	TIM2_ARRH = 0x00;
	TIM2_ARRL = 0xFF;


	//初始化比较寄存器，决定PWM 方波的占空比
	TIM2_CCR1H = 0;
	TIM2_CCR1L = 0;
	TIM2_CCR2H = 0;
	TIM2_CCR2L = 0;

	
	TIM2_CR1 = 0x01;// 启动计数
}

//装占空比 产生50Hz方波的TIM4中断程序
@far @interrupt void TIM4_UPD_OVF_IRQHandler (void)
{
	TIM4_SR = 0x00; // 清除更新标志

	//设置占空比
	duty_cycle=pwm[period];

	//更新占空比
	if(Pin_Sync){ 
		TIM2_CCR1L=0;
		TIM2_CCR2L=duty_cycle;
	}else{
		TIM2_CCR1L=duty_cycle;
		TIM2_CCR2L=0;
	}

	period++;
	if(period>160){
		period=0;
		Pin_Sync=~Pin_Sync; //反向50Hz同步方波
	}
}

//猪程序
void main(void)
{
	CLK_CKDIVR = 0x00;	//CPU全速工作>_< 16MHz!
	
	Init_50Hz();
	Init_PWM();
	_asm("rim"); //开中断
	
	//GPIO初始化
	PB_DDR=0x30;
	PB_CR1=0x30;
	PB_CR2=0x00;
	
	while (1);
}