STC32G系列高速PWM使用PLL时钟源实现高速输出和高速捕获功能
STC32G系列单片机的高速PWM可以和CPU工作在不同频率STC32G12K128系列CPU最高工作频率可达35MHz
STC32G8K64系列CPU最高工作频率可达42MHz
上面两个系列的高级PWM均可工作在144MHz
系统时钟树选择如下：
范例说明：
1、时钟说明：由内部IRC产生12MHz的时钟提供给PLL当作PLL输入时钟，PLL锁频到144MHz输出作为高速PWM的时钟源，
同时144MHz的PLL输出时钟通过CLKDIV进行4或者5分频，产生36MHz或者28.8MHz的时钟提供给CPU当作系统工作频率
2、PWM高速输出说明：PWMA的CC1通道配置为输出模式，并从P2.0口输出频率为28.8MHz，占空比为40％的PWM型号
3、PWM高速捕获说明：PWMB的CC5和CC6通道配置为捕获输入模式，CC5口P2.0口捕获信号的周期值，CC6从P2.0口捕获信号的占空比
4、测试说明：最后通过查询方式得到周期值和占空比并从串口送到PC显示
#include "stc32g.h"
#include "stdio.h"
#include "intrins.h"
#define FOSC 12000000UL
#define PLLCLK 144000000UL
#define MCLKDIV 4 //144M/4=36M
//#define MCLKDIV 5 //144M/5=28.8M
#define MCLK PLLCLK
#define SYSCLK MCLK/MCLKDIV
#define BAUD (65536 - SYSCLK/4/115200)
#define MCLK_HIRC 0
#define MCLK_IRC32K 1
#define MCLK_IRC48M 2
#define MCLK_XOSC 3
#define MCLK_X32K 4
#define MCLK_PLL 5
#define MCLK_PLLD2 6
#define MCLK_SEL MCLK_PLL
#define HSCK_MCLK 0
#define HSCK_PLL 1
#define HSCK_SEL HSCK_PLL
#define PLL_96M 0
#define PLL_144M 1
#define PLL_SEL PLL_144M
#define CKMS 0x80
#define HSIOCK 0x40
#define MCK2SEL_MSK 0x0c
#define MCK2SEL_SEL1 0x00
#define MCK2SEL_PLL 0x04
#define MCK2SEL_PLLD2 0x08
#define MCK2SEL_IRC48 0x0c
#define MCKSEL_MSK 0x03
#define MCKSEL_HIRC 0x00
#define MCKSEL_XOSC 0x01
#define MCKSEL_X32K 0x02
#define MCKSEL_IRC32K 0x03
#define ENCKM 0x80
#define PCKI_MSK 0x60
#define PCKI_D1 0x00
#define PCKI_D2 0x20
#define PCKI_D4 0x40
#define PCKI_D8 0x60
void delay()
{
int i;
for (i=0; i<100; i++);
}
char ReadPWMA(char addr)
{
char dat;
while (HSPWMA_ADR & 0x80); //等待前一个异步读写完成
HSPWMA_ADR = addr | 0x80; //设置间接访问地址,只需要设置原XFR地址的低7位
//HSPWMA_ADDR寄存器的最高位写1,表示读数据
while (HSPWMA_ADR & 0x80); //等待当前异步读取完成
dat = HSPWMA_DAT; //读取异步数据
return dat;
}
void WritePWMA(char addr, char dat)
{
while (HSPWMA_ADR & 0x80); //等待前一个异步读写完成
HSPWMA_DAT = dat; //准备需要写入的数据
HSPWMA_ADR = addr & 0x7f; //设置间接访问地址,只需要设置原XFR地址的低7位
//HSPWMA_ADDR寄存器的最高位写0,表示写数据
}
char ReadPWMB(char addr)
{
char dat;
while (HSPWMB_ADR & 0x80); //等待前一个异步读写完成
HSPWMB_ADR = addr | 0x80; //设置间接访问地址,只需要设置原XFR地址的低7位
//HSPWMB_ADDR寄存器的最高位写1,表示读数据
while (HSPWMB_ADR & 0x80); //等待当前异步读取完成
dat = HSPWMB_DAT; //读取异步数据
return dat;
}
void WritePWMB(char addr, char dat)
{
while (HSPWMB_ADR & 0x80); //等待前一个异步读写完成
HSPWMB_DAT = dat; //准备需要写入的数据
HSPWMB_ADR = addr & 0x7f; //设置间接访问地址,只需要设置原XFR地址的低7位
//HSPWMB_ADDR寄存器的最高位写0,表示写数据
}
void main()
{
WTST = 0x00;
P_SW2 = 0x80;
P0M0 = 0x00; P0M1 = 0x00;
P1M0 = 0x00; P1M1 = 0x00;
P2M0 = 0x00; P2M1 = 0x00;
P3M0 = 0x00; P3M1 = 0x00;
P5M0 = 0x10; P5M1 = 0x00;
SCON = 0x52;
AUXR = 0x40;
TMOD = 0x00;
TL1 = BAUD;
TH1 = BAUD >> 8;
TR1 = 1;
//选择PLL输出时钟
#if (PLL_SEL == PLL_96M)
CLKSEL &= ~CKMS; //选择PLL的96M作为PLL的输出时钟
#elif (PLL_SEL == PLL_144M)
CLKSEL |= CKMS; //选择PLL的144M作为PLL的输出时钟
#else
CLKSEL &= ~CKMS; //默认选择PLL的96M作为PLL的输出时钟
#endif
//选择PLL输入时钟分频,保证输入时钟为12M
USBCLK &= ~PCKI_MSK;
#if (FOSC == 12000000UL)
USBCLK |= PCKI_D1; //PLL输入时钟1分频
#elif (FOSC == 24000000UL)
USBCLK |= PCKI_D2; //PLL输入时钟2分频
#elif (FOSC == 48000000UL)
USBCLK |= PCKI_D4; //PLL输入时钟4分频
#elif (FOSC == 96000000UL)
USBCLK |= PCKI_D8; //PLL输入时钟8分频
#else
USBCLK |= PCKI_D1; //默认PLL输入时钟1分频
#endif
//启动PLL
USBCLK |= ENCKM; //使能PLL倍频
delay(); //等待PLL锁频
//选择主时钟源
CLKDIV = MCLKDIV; //主时钟选择高速频率前,必须先设置分频系数,否则程序会当掉
CLKSEL &= ~MCKSEL_MSK;
CLKSEL &= ~MCK2SEL_MSK;
#if (MCLK_SEL == MCLK_HIRC)
CLKSEL |= MCKSEL_HIRC; //选择内部高速IRC作为主时钟
CLKSEL |= MCK2SEL_SEL1; //选择MCKSEL选择的时钟作为主时钟
#elif (MCLK_SEL == MCLK_IRC32K)
CLKSEL |= MCKSEL_X32K; //选择外部32K作为主时钟
CLKSEL |= MCK2SEL_SEL1; //选择MCKSEL选择的时钟作为主时钟
#elif (MCLK_SEL == MCLK_IRC48M)
CLKSEL |= MCKSEL_HIRC; //选择内部高速IRC作为主时钟
CLKSEL |= MCK2SEL_IRC48; //选择内部48M的IRC作为主时钟
#elif (MCLK_SEL == MCLK_XOSC)
CLKSEL |= MCKSEL_XOSC; //选择外部高速晶振作为主时钟
CLKSEL |= MCK2SEL_SEL1; //选择MCKSEL选择的时钟作为主时钟
#elif (MCLK_SEL == MCLK_X32K)
CLKSEL |= MCKSEL_IRC32K; //选择内部低速IRC作为主时钟
CLKSEL |= MCK2SEL_SEL1; //选择MCKSEL选择的时钟作为主时钟
#elif (MCLK_SEL == MCLK_PLL)
CLKSEL |= MCKSEL_HIRC; //选择内部高速IRC作为主时钟
CLKSEL |= MCK2SEL_PLL; //选择PLL输出时钟作为主时钟
#elif (MCLK_SEL == MCLK_PLLD2)
CLKSEL |= MCKSEL_HIRC; //选择内部高速IRC作为主时钟
CLKSEL |= MCK2SEL_PLLD2; //选择PLL输出时钟2分频后的时钟作为主时钟
#else
CLKSEL |= MCKSEL_HIRC; //默认选择内部高速IRC作为主时钟
CLKSEL |= MCK2SEL_SEL1; //默认选择MCKSEL选择的时钟作为主时钟
#endif
MCLKOCR = 0x04; //系统时钟4分频后输出到P5.4口
//选择HSPWM/HSSPI时钟
#if (HSCK_SEL == HSCK_MCLK)
CLKSEL &= ~HSIOCK; //HSPWM/HSSPI选择主时钟为时钟源
#elif (HSCK_SEL == HSCK_PLL)
CLKSEL |= HSIOCK; //HSPWM/HSSPI选择PLL输出时钟为时钟源
#else
CLKSEL &= ~HSIOCK; //默认HSPWM/HSSPI选择主时钟为时钟源
#endif
HSCLKDIV = 0; //HSPWM/HSSPI时钟源不分频
HSPWMA_CFG = 0x03; //使能PWMA相关寄存器异步访问功能
HSPWMB_CFG = 0x03; //使能PWMB相关寄存器异步访问功能
PWMA_PS = 0x01; //PWMA_CC1高速PWM输出到P2.0口
//PWMB_CC5从P2.0口进行捕获
//通过异步方式设置PWMA/PWMB的相关寄存器
WritePWMA((char)&PWMA_CCER1, 0x00);
WritePWMA((char)&PWMA_CCMR1, 0x00); //CC1为输出模式
WritePWMA((char)&PWMA_CCMR1, 0x60); //OC1REF输出PWM1(CNT<CCR时输出有效电平1)
WritePWMA((char)&PWMA_CCER1, 0x05); //使能CC1/CC1N上的输出功能
WritePWMA((char)&PWMA_ENO, 0x03); //使能PWM信号输出到端口
WritePWMA((char)&PWMA_BKR, 0x80); //使能主输出
WritePWMA((char)&PWMA_CCR1H, 0x00); //设置输出PWM的占空比
WritePWMA((char)&PWMA_CCR1L, 0x02);
WritePWMA((char)&PWMA_ARRH, 0x00); //设置输出PWM的周期
WritePWMA((char)&PWMA_ARRL, 0x04);
WritePWMA((char)&PWMA_CR1, 0x01); //开始PWM计数
WritePWMB((char)&PWMB_CCER1, 0x00);
WritePWMB((char)&PWMB_CCMR1, 0x01); //CC5为输入模式,且映射到TI5FP5上
WritePWMB((char)&PWMB_CCMR2, 0x02); //CC6为输入模式,且映射到TI6FP5上
WritePWMB((char)&PWMB_CCER1, 0x31); //使能CC5上的捕获功能(上升沿捕获)
WritePWMB((char)&PWMB_SMCR, 0x54); //上升沿复位模式
WritePWMB((char)&PWMB_CR1, 0x01); //开始PWM计数
while (1)
{
if (ReadPWMB((char)&PWMB_SR1) & 0x02) //等待捕获完成
{
WritePWMB((char)&PWMB_SR1, 0x00); //清除完成标志
//读取捕获到的周期值
printf("%02x", (unsigned int)ReadPWMB((char)&PWMB_CCR5H) & 0xff);
printf("%02x", (unsigned int)ReadPWMB((char)&PWMB_CCR5L) & 0xff);
printf(" ");
//读取捕获到的占空比值
printf("%02x", (unsigned int)ReadPWMB((char)&PWMB_CCR6H) & 0xff);
printf("%02x", (unsigned int)ReadPWMB((char)&PWMB_CCR6L) & 0xff);
printf("\n");
}
}
}
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