关于stc15系列硬件pwm库函数的疑惑，求解答
本帖最后由 zjb12702881 于 2023-3-5 13:04 编辑/*------------------------------------------------------------------*/
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/* If you want to use the program or the program referenced in the*/
/* article, please specify in which data and procedures from STC */
/*------------------------------------------------------------------*/
#include "PCA.h"
bit B_Capture0,B_Capture1,B_Capture2;
u8 PCA0_mode,PCA1_mode,PCA2_mode;
u16 CCAP0_tmp,PCA_Timer0;
u16 CCAP1_tmp,PCA_Timer1;
u16 CCAP2_tmp,PCA_Timer2;
/************* 功能说明 **************
******************************************/
//========================================================================
// 函数: UpdatePwm(u8 PCA_id, u8 pwm_value)
// 描述: 更新PWM值.
// 参数: PCA_id: PCA序号. 取值 PCA0,PCA1,PCA2,PCA_Counter
// pwm_value: pwm值, 这个值是输出低电平的时间.
// 返回: none.
// 版本: V1.0, 2012-11-22
//========================================================================
void UpdatePwm(u8 PCA_id, u8 pwm_value)
{
if(PCA_id == PCA0) CCAP0H = pwm_value;
else if(PCA_id == PCA1) CCAP1H = pwm_value;
else if(PCA_id == PCA2) CCAP2H = pwm_value;
}
//========================================================================
// 函数: void PCA_Init(PCA_id, PCA_InitTypeDef *PCAx)
// 描述: PCA初始化程序.
// 参数: PCA_id: PCA序号. 取值 PCA0,PCA1,PCA2,PCA_Counter
// PCAx: 结构参数,请参考PCA.h里的定义.
// 返回: none.
// 版本: V1.0, 2012-11-22
//========================================================================
void PCA_Init(u8 PCA_id, PCA_InitTypeDef *PCAx)
{
if(PCA_id > PCA_Counter) return; //id错误
if(PCA_id == PCA_Counter) //设置公用Counter
{
CR = 0;
CH = 0;
CL = 0;
/**************A =&~(B<<C);将A从第C位开始的B位数清零*************/
/**************A = |(B<<C);将A从第C位开始的B位数置1*************/
AUXR1 = (AUXR1 & ~(3<<4)) | PCAx->PCA_IoUse; //切换IO口，将AUXR1的第四位开始连续的两位先置零然后或上PCAx->PCA_IoUse
CMOD= (CMOD& ~(7<<1)) | PCAx->PCA_Clock; //选择时钟源,将COMD的第一位开始连续三位先置零然后或上PCAx->PCA_Clock
CMOD= (CMOD& ~1) | (PCAx->PCA_Interrupt_Mode & 1); //ECF
if(PCAx->PCA_Polity == PolityHigh) PPCA = 1; //高优先级中断
else PPCA = 0; //低优先级中断
if(PCAx->PCA_RUN == ENABLE) CR = 1;
return;
}
PCAx->PCA_Interrupt_Mode &= (3<<4) + 1;
if(PCAx->PCA_Mode >= PCA_Mode_SoftTimer) PCAx->PCA_Interrupt_Mode &= ~(3<<4);
if(PCA_id == PCA0)
{
CCAPM0 = PCAx->PCA_Mode | PCAx->PCA_Interrupt_Mode; //工作模式, 中断模式
PCA_PWM0= (PCA_PWM0 & ~(3<<6)) | PCAx->PCA_PWM_Wide; //PWM宽度
PCA_Timer0 = PCAx->PCA_Value;
B_Capture0 = 0;
PCA0_mode = PCAx->PCA_Mode;
CCAP0_tmp = PCA_Timer0;
CCAP0L = (u8)CCAP0_tmp; //将影射寄存器写入捕获寄存器，先写CCAP0L
CCAP0H = (u8)(CCAP0_tmp >> 8); //后写CCAP0H
}
if(PCA_id == PCA1)
{
CCAPM1 = PCAx->PCA_Mode | PCAx->PCA_Interrupt_Mode;
PCA_PWM1= (PCA_PWM1 & ~(3<<6)) | PCAx->PCA_PWM_Wide;
PCA_Timer1 = PCAx->PCA_Value;
B_Capture1 = 0;
PCA1_mode = PCAx->PCA_Mode;
CCAP1_tmp = PCA_Timer1;
CCAP1L = (u8)CCAP1_tmp; //将影射寄存器写入捕获寄存器，先写CCAP0L
CCAP1H = (u8)(CCAP1_tmp >> 8); //后写CCAP0H
}
if(PCA_id == PCA2)
{
CCAPM2 = PCAx->PCA_Mode | PCAx->PCA_Interrupt_Mode;
PCA_PWM2= (PCA_PWM2 & ~(3<<6)) | PCAx->PCA_PWM_Wide;
PCA_Timer2 = PCAx->PCA_Value;
B_Capture2 = 0;
PCA2_mode = PCAx->PCA_Mode;
CCAP2_tmp = PCA_Timer2;
CCAP2L = (u8)CCAP2_tmp; //将影射寄存器写入捕获寄存器，先写CCAP0L
CCAP2H = (u8)(CCAP2_tmp >> 8); //后写CCAP0H
}
}
//========================================================================
// 函数: void PCA_Handler (void) interrupt PCA_VECTOR
// 描述: PCA中断处理程序.
// 参数: None
// 返回: none.
// 版本: V1.0, 2012-11-22
//========================================================================
void PCA_Handler (void) interrupt PCA_VECTOR
{
if(CCF0) //PCA模块0中断
{
CCF0 = 0; //清PCA模块0中断标志
if(PCA0_mode >= PCA_Mode_SoftTimer) //PCA_Mode_SoftTimer and PCA_Mode_HighPulseOutput
{
CCAP0_tmp += PCA_Timer0;
CCAP0L = (u8)CCAP0_tmp; //将影射寄存器写入捕获寄存器，先写CCAP0L
CCAP0H = (u8)(CCAP0_tmp >> 8); //后写CCAP0H
}
else if(PCA0_mode == PCA_Mode_Capture)
{
CCAP0_tmp = CCAP0H; //读CCAP0H
CCAP0_tmp = (CCAP0_tmp << 8) + CCAP0L;
B_Capture0 = 1;
}
}
if(CCF1) //PCA模块1中断
{
CCF1 = 0; //清PCA模块1中断标志
if(PCA1_mode >= PCA_Mode_SoftTimer) //PCA_Mode_SoftTimer and PCA_Mode_HighPulseOutput
{
CCAP1_tmp += PCA_Timer1;
CCAP1L = (u8)CCAP1_tmp; //将影射寄存器写入捕获寄存器，先写CCAP0L
CCAP1H = (u8)(CCAP1_tmp >> 8); //后写CCAP0H
}
else if(PCA1_mode == PCA_Mode_Capture)
{
CCAP1_tmp = CCAP1H; //读CCAP1H
CCAP1_tmp = (CCAP1_tmp << 8) + CCAP1L;
B_Capture1 = 1;
}
}
if(CCF2) //PCA模块2中断
{
CCF2 = 0; //清PCA模块1中断标志
if(PCA2_mode >= PCA_Mode_SoftTimer) //PCA_Mode_SoftTimer and PCA_Mode_HighPulseOutput
{
CCAP2_tmp += PCA_Timer2;
CCAP2L = (u8)CCAP2_tmp; //将影射寄存器写入捕获寄存器，先写CCAP0L
CCAP2H = (u8)(CCAP2_tmp >> 8); //后写CCAP0H
}
else if(PCA2_mode == PCA_Mode_Capture)
{
CCAP2_tmp = CCAP2H; //读CCAP2H
CCAP2_tmp = (CCAP2_tmp << 8) + CCAP2L;
B_Capture2 = 1;
}
}
if(CF) //PCA溢出中断
{
CF = 0; //清PCA溢出中断标志
}
}
PCA上面的变量bit B_Capture0,B_Capture1,B_Capture2;在pca.c中也就是上面的代码区出现了，三个变量是什么变量为什么在中断里在置 1 ，在void PCA_Init(u8 PCA_id, PCA_InitTypeDef *PCAx)初始化函数里置 0，这个变量表达的是什么意思那？这个变量在结构体指针变量PCA_InitTypeDef *PCAx里面也没有为何在初始化中置 0，中断里面置1？
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