STC MCU PWM pulse width modulation function module

#include

// PWM initialization
// Initialize PCA to PWM mode with an initial duty cycle of 0
// Parameters: 0, 1, 2, 3, representing initialization of PWM0, PWM1, PWM2, and PWM3 respectively
void PWM_Init(int i)
{
 CMOD = 0x02; // Set the PCA timer frequency to the internal clock fosc/2
 CL = 0x00;
 CH = 0x00;

 switch(i)
 {
  case 0:
   CCAPM0 = 0x42; // PWM0 sets PCA working mode to PWM mode (0100 0010)
   CCAP0L = 0x00; // Set the initial value of PWM0 to be the same as CCAP0H
   CCAP0H = 0x00; // PWM0 is initially 0
   break;
  case 1:
   CCAPM1 = 0x42;
   CCAP1L = 0x00;
   CCAP1H = 0x00;
   break;
  case 2:
   CCAPM2 = 0x42;
   CCAP2L = 0x00;
   CCAP2H = 0x00;
   break;
  case 3:
   CCAPM3 = 0x42;
   CCAP3L = 0x00;
   CCAP3H = 0x00;
   break;
  default:
   break;
 }

 CR = 1; // Start PCA timer
}

// PWM duty cycle setting
// Parameter 1: 0, 1, 2, 3, respectively represent setting the duty cycle for PWM0, PWM1, PWM2, and PWM3
// Parameter 2: 0x00~0xFF (or 0~255), all low level when 0x00, all high level when 0xFF
void PWM_Set(int i, unsigned char c)
{
 switch(i)
 {
  case 0: 
   CCAP0L = c;
   CCAP0H = c;
   break;
  case 1:
   CCAP1L = c;
   CCAP1H = c;
   break; case
  2:
   CCAP2L = c;
   CCAP2H = c;
   break;
  case 3:
   CCAP3L = c;
   CCAP3H = c;
   break;
  default:
   break;
 }
}