//ccr = 0~499

void setPWM1(unsigned short ccr){//PC1

  TIM1_CCR1H = (unsigned char)(ccr>>8);

  TIM1_CCR1L = (unsigned char)(ccr & 0xff);

}

void setPWM2(unsigned short ccr){//PC2

  TIM1_CCR2H = (unsigned char)(ccr>>8);

  TIM1_CCR2L = (unsigned char)(ccr & 0xff);

}

void setPWM3(unsigned short ccr){//PC3

  TIM1_CCR3H = (unsigned char)(ccr>>8);

  TIM1_CCR3L = (unsigned char)(ccr & 0xff);  

}

void setPWM4(unsigned short ccr){//PC4

  TIM1_CCR4H = (unsigned char)(ccr>>8);

  TIM1_CCR4L = (unsigned char)(ccr & 0xff);

}

void TIM1_init(void)

{

  TIM1_PSCRH = 0x01;    // 8M系統時鐘經預分頻f=fck/(PSCR+1)

  TIM1_PSCRL = 0x3F;    // PSCR=0x13f，f=8M/(0x13F+1)=25 000Hz，每個計數周期40us

  TIM1_ARRH = 0x01;     // 自動重載寄存器ARR=0x01F4=500

  TIM1_ARRL = 0xF4;     // 每記數500次產生一次中斷，即20ms

  /**

  * PWM 配置

  */

  PC_DDR |= 0x1E; PC_CR1 |= 0x1E; PC_ODR &= ~0x1E;

  TIM1_CCMR1 = 0x78;

  TIM1_CCMR2 = 0x78;

  TIM1_CCMR3 = 0x78;

  TIM1_CCMR4 = 0x78;// Output mode PWM2.

                    // 通道 2 被設置成比較輸出方式, OC2M = 111,為 PWM 模式 2, 向上計數時，若計數器小于比較值，為無效電平

  TIM1_CCER1 = 0x33;

  TIM1_CCER2 = 0x33;// CC polarity low,enable PWM output */

                    // CC2P = 1，低電平為有效電平

                    // CC2E = 1，開啟輸出引腳

  //設置占空比

  setPWM1(0);  setPWM2(0);

  setPWM3(0);  setPWM4(0);

  TIM1_EGR=0X01; //重新初始化計數器，并產生一個更新事件，可以不要

  TIM1_BKR=0x80; //主輸出使能，必須要有

  TIM1_IER = 0x01;      // 允許更新中斷

  TIM1_CR1 = 0x01;      // 計數器使能，開始計數

}

//main()

    int i = 0;

    for(i=0;i<23;i++){ setPWM1(i*i);delay_ms(50); }

    for(i=22;i>0;i--){ setPWM1(i*i);delay_ms(50); }

    for(i=0;i<23;i++){ setPWM2(i*i);delay_ms(50); }

    for(i=22;i>0;i--){ setPWM2(i*i);delay_ms(50); }

    for(i=0;i<23;i++){ setPWM3(i*i);delay_ms(50); }

    for(i=22;i>0;i--){ setPWM3(i*i);delay_ms(50); }

    for(i=0;i<23;i++){ setPWM4(i*i);delay_ms(50); }

    for(i=22;i>0;i--){ setPWM4(i*i);delay_ms(50); }

    setPWM1(0);  setPWM2(0);

    setPWM3(0);  setPWM4(0);

    delay_ms(3000);*/