ePWM module - time base module (2)

ePWM Modules (2)

Use of time base module

TBPRD: period register (the set clock period is stored here, it can be written after buffering through the shadow register, or it can be written immediately through the active register)

TBCTR: time base count variable value register (the value currently counted by the time base is stored for comparison with the set period value)
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TBPHS: Time Base Phase Register
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TBSTS: Time Base Status Register
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TBCTL: control register (important)

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CTRMOD: counting mode
00: add
01: subtract
10: add and subtract
11: stop counting

PHSEN: enable phase
0: disable loading
1: load phase register value

PRDLD: Period register shadow loading mode
0: Load shadow register value
1: Do not load shadow

SYNCOSEL: Select ePWMxSYNCO signal output source
00: ePWMxSYNCI
01: CTR=ZER0: Time base counter is 0
10: CTR=CMPA: Time base counter is equal to compare register A
11: Disable output

SWFSYNC: software forced synchronization pulse
0: no effect
1: forced once

HSPCLKDIV: frequency division, same as CLKDIV. TBCLK=SYSCLKOUT/(HSPCLKDIV×CLKDIV)

CLKDIV: frequency division, same as HSPCLKDIV with
000: 1 frequency division
001: 2 frequency division
010: 4 frequency division
...
111: 128 frequency division

PHSDIR: In the increase-decrease mode, when the synchronization signal arrives, the counting direction of the increase-decrease state after loading the phase value
0: count down
1: count up

#include "EPWM.h"
#include "leds.h"

//时基模块 TB 单独的应用,使用中断实现呼吸灯
void EPWM1_Init(Uint16 tbprd) //输入参数为PWM的周期
{
    //使能 ePWM 外设时钟及失能时基模块时钟
    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;//失能TBCLKSYNC
    SysCtrlRegs.PCLKCR1.bit.EPWM1ENCLK = 1;//使能ePWM1外设时钟
    EDIS;

    //中断向量表
    EALLOW;
    PieVectTable.EPWM1_INT = &epwm1_timer_isr;
    EDIS;

    //使能时基时钟
    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0;//使能TBCLKSYNC
    EDIS;

    //设置同步
    EPwm1Regs.TBCTL.bit.SYNCOSEL= 0x0;//TB_SYNC_IN
    //允许每个使用被同步
    EPwm1Regs.TBCTL.bit.PHSEN = 0x1;//TB_ENABLE
    时基相位寄存器赋值0
    EPwm1Regs.TBPHS.half.TBPHS = 0;
    //设置周期数值
    EPwm1Regs.TBPRD = tbprd;
    // 递增计数模式
    EPwm1Regs.TBCTL.bit.CTRMODE = 0x0;//TB_COUNT_UP
    //TBCLK=SYSCLKOUT/（HSPCLKDIV×CLKDIV）
    EPwm1Regs.TBCTL.bit.HSPCLKDIV=0x0;//不分频TB_DIV1
    EPwm1Regs.TBCTL.bit.CLKDIV=0x0;//不分频TB_DIV1
    // 在零事件上选择INT
    EPwm1Regs.ETSEL.bit.INTSEL = 0x1;//ET_CTR_ZERO
    // 使能 INT
    EPwm1Regs.ETSEL.bit.INTEN = 1;  //ET_1ST
    // 在第一个事件上生成INT
    EPwm1Regs.ETPS.bit.INTPRD = 0x1;
    // 同步启动所有计时器
    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;
    EDIS;

    // 使能连接EPWM1-6 INT的CPU INT3:
    IER |= M_INT3;

    // 使能PIE中的EPWM INTn:组3中断1-6
    PieCtrlRegs.PIEIER3.bit.INTx1 = 1;

   // 启用全局中断和更高优先级的实时调试事件:
   EINT;   // 启用全局中断INTM
   ERTM;   // 启用全局实时中断DBGM
}

interrupt void epwm1_timer_isr(void)
{
    static Uint16 cnt = 0;
    cnt++;
    if(cnt==5000)
    {
        cnt=0;
        LED3_TOGGLE;
    }
    // 清除此计时器的INT标志
    EPwm1Regs.ETCLR.bit.INT = 1;
    // 确认此中断以接收来自组3的更多中断
    PieCtrlRegs.PIEACK.bit.ACK3 = 1;
}

#ifndef APP_EPWM_EPWM_H_
#define APP_EPWM_EPWM_H_

#include "DSP2833x_Device.h"     // DSP2833x 头文件
#include "DSP2833x_Examples.h"   // DSP2833x 例子相关头文件

void EPWM1_Init(Uint16 tbprd);
interrupt void epwm1_timer_isr(void);



#endif /* APP_EPWM_EPWM_H_ */