STC8A增強型PWM可以自由設(shè)定高低電平位置。頻率必須相同，占空比和相位隨便調(diào)。
范例：
#include "reg51.h"
#include "intrins.h"
//測試工作頻率為11.0592MHz
sfr P_SW2 = 0xba;
sfr PWMCFG = 0xf1;
sfr PWMIF = 0xf6;
sfr PWMFDCR = 0xf7;
sfr PWMCR = 0xfe;
#define PWMC (*(unsigned int volatile xdata *)0xfff0)
#define PWMCKS (*(unsigned char volatile xdata *)0xfff2)
#define TADCP (*(unsigned int volatile xdata *)0xfff3)
#define PWM0T1 (*(unsigned int volatile xdata *)0xff00)
#define PWM0T2 (*(unsigned int volatile xdata *)0xff02)
#define PWM0CR (*(unsigned char volatile xdata *)0xff04)
#define PWM0HLD (*(unsigned char volatile xdata *)0xff05)
#define PWM1T1 (*(unsigned int volatile xdata *)0xff10)
#define PWM1T2 (*(unsigned int volatile xdata *)0xff12)
#define PWM1CR (*(unsigned char volatile xdata *)0xff14)
#define PWM1HLD (*(unsigned char volatile xdata *)0xff15)
#define PWM2T1 (*(unsigned int volatile xdata *)0xff20)
#define PWM2T2 (*(unsigned int volatile xdata *)0xff22)
#define PWM2CR (*(unsigned char volatile xdata *)0xff24)
#define PWM2HLD (*(unsigned char volatile xdata *)0xff25)
#define PWM3T1 (*(unsigned int volatile xdata *)0xff30)
#define PWM3T2 (*(unsigned int volatile xdata *)0xff32)
#define PWM3CR (*(unsigned char volatile xdata *)0xff34)
#define PWM3HLD (*(unsigned char volatile xdata *)0xff35)
#define PWM4T1 (*(unsigned int volatile xdata *)0xff40)
#define PWM4T2 (*(unsigned int volatile xdata *)0xff42)
#define PWM4CR (*(unsigned char volatile xdata *)0xff44)
#define PWM4HLD (*(unsigned char volatile xdata *)0xff45)
#define PWM5T1 (*(unsigned int volatile xdata *)0xff50)
#define PWM5T2 (*(unsigned int volatile xdata *)0xff52)
#define PWM5CR (*(unsigned char volatile xdata *)0xff54)
#define PWM5HLD (*(unsigned char volatile xdata *)0xff55)
#define PWM6T1 (*(unsigned int volatile xdata *)0xff60)
#define PWM6T2 (*(unsigned int volatile xdata *)0xff62)
#define PWM6CR (*(unsigned char volatile xdata *)0xff64)
#define PWM6HLD (*(unsigned char volatile xdata *)0xff65)
#define PWM7T1 (*(unsigned int volatile xdata *)0xff70)
#define PWM7T2 (*(unsigned int volatile xdata *)0xff72)
#define PWM7CR (*(unsigned char volatile xdata *)0xff74)
#define PWM7HLD (*(unsigned char volatile xdata *)0xff75)
void main()
{
P_SW2 = 0x80;
PWMCKS = 0x00; // PWM時鐘為系統(tǒng)時鐘
PWMC = 0x0800; //設(shè)置PWM周期為0800H個PWM時鐘
PWM0T1= 0x0100; //PWM0在計數(shù)值為100H地方輸出低電平
PWM0T2= 0x0700; //PWM0在計數(shù)值為700H地方輸出高電平
PWM1T2= 0x0080; //PWM1在計數(shù)值為0080H地方輸出高電平
PWM1T1= 0x0780; //PWM1在計數(shù)值為0780H地方輸出低電平
PWM0CR= 0x80; //使能PWM0輸出
PWM1CR= 0x80; //使能PWM1輸出
P_SW2 = 0x00;
PWMCR = 0x80; //啟動PWM模塊
while (1);
}
說明：PWM0,PWM1高低電平的位置是可以設(shè)置的，也就是相位，占空比可以隨意，但是頻率必須一樣。 |
PWM波是直接用STC8A帶的pwm寄存器生成的。代碼如下：
