tms32f28033中的模拟比较器问题

你的DAC的reference现在设置的不是1.5V，你是怎么判断现在有问题的？

以下是一个根据controlsuite例程改的使用内部DAC 设置为1.65V 比较点，然后通过触发比较器可以触发EPWM4 oneshot事件，并且在EPWM4周期中断清标志的例子，你可以参考下。

#include "DSP28x_Project.h" // Device Headerfile and Examples Include File

// Prototype statements for functions found within this file.
void InitEPwm4Example(void);
void InitComp2(void);
__interrupt void epwm4_tzint_isr(void);

// Global variables used in this example
uint32_t EPwm4TZIntCount;
uint32_t EPwm2TZIntCount;

void main(void)
{

// WARNING: Always ensure you call memcpy before running any functions from RAM
// InitSysCtrl includes a call to a RAM based function and without a call to
// memcpy first, the processor will go "into the weeds"
#ifdef _FLASH
memcpy(&RamfuncsRunStart, &RamfuncsLoadStart, (size_t)&RamfuncsLoadSize);
#endif

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the f2802x_SysCtrl.c file.
InitSysCtrl();

// Step 2. Initalize GPIO:
// This example function is found in the f2802x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio(); // Skipped for this example

// For this case just init GPIO pins for ePWM1, ePWM2, and TZ pins
InitEPwm4Gpio();
InitComp2();
EALLOW;

GpioCtrlRegs.GPBMUX1.bit.GPIO33 = 0; // Configure GPIO6 as EPWM4A
GpioCtrlRegs.GPBDIR.bit.GPIO33 = 1;
GpioDataRegs.GPBCLEAR.bit.GPIO33 = 1;

EDIS;
// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
DINT;

// Initialize the PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the f2802x_PieCtrl.c file.
InitPieCtrl();

// Disable CPU interrupts and clear all CPU interrupt flags:
IER = 0x0000;
IFR = 0x0000;

// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example. This is useful for debug purposes.
// The shell ISR routines are found in f2802x_DefaultIsr.c.
// This function is found in f2802x_PieVect.c.
InitPieVectTable();

// Interrupts that are used in this example are re-mapped to
// ISR functions found within this file.
EALLOW; // This is needed to write to EALLOW protected registers
PieVectTable.EPWM4_TZINT = &epwm4_tzint_isr;
EDIS; // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in f2802x_InitPeripherals.c
// InitPeripherals(); // Not required for this example

//------------------------------------------------------------------
//////////////////////////////////////////////////////////////////////////////////////////////
EDIS;
//------------------------------------------------------------------
EALLOW;
SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0;
EDIS;

InitEPwm4Example();

EALLOW;
SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;
EDIS;

// Step 5. User specific code, enable interrupts
// Initalize counters:
EPwm4TZIntCount = 0;

// Enable CPU INT3 which is connected to EPWM1-3 INT:
IER |= M_INT2;

// Enable EPWM INTn in the PIE: Group 2 interrupt 1-3
PieCtrlRegs.PIEIER2.bit.INTx4 = 1;

// Enable global Interrupts and higher priority real-time debug events:
EINT; // Enable Global interrupt INTM
ERTM; // Enable Global realtime interrupt DBGM

// Step 6. IDLE loop. Just sit and loop forever (optional):
for(;;)
{
__asm(" NOP");
}

}

__interrupt void epwm4_tzint_isr(void)
{
EPwm4TZIntCount++;

// Leave these flags set so we only take this
// interrupt once
//
EALLOW;
// EPwm4Regs.TZCLR.bit.OST = 1;
// EPwm4Regs.TZCLR.bit.INT = 1;
EPwm4Regs.TZCLR.bit.DCAEVT1 = 1;
EPwm4Regs.TZCLR.bit.INT = 1;
EPwm4Regs.TZCLR.bit.OST = 1;
GpioDataRegs.GPBDAT.bit.GPIO33 = EPwm4Regs.TZFLG.bit.OST;

EDIS;

// Acknowledge this interrupt to receive more interrupts from group 2
PieCtrlRegs.PIEACK.all = PIEACK_GROUP2;

}

void InitEPwm4Example()
{

EALLOW;
EPwm4Regs.TBPRD = 6000; // Set timer period
EPwm4Regs.TBPHS.half.TBPHS = 0x0000; // Phase is 0
EPwm4Regs.TBCTR = 0x0000;

// Setup TBCLK
EPwm4Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Count up/down
EPwm4Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Disable phase loading
EPwm4Regs.TBCTL.bit.HSPCLKDIV = TB_DIV4; // Clock ratio to SYSCLKOUT
EPwm4Regs.TBCTL.bit.CLKDIV = TB_DIV4;

EPwm4Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW; // Load registers every ZERO
EPwm4Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
EPwm4Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;
EPwm4Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO;

// Setup compare
EPwm4Regs.CMPA.half.CMPA = 3000;

// Set actions
EPwm4Regs.AQCTLA.bit.CAU = AQ_SET; // Set PWM1A on Zero
// EPwm4Regs.AQCTLA.bit.CAU = AQ_CLEAR; // Set PWM1A on Zero
EPwm4Regs.AQCTLA.bit.CAD = AQ_CLEAR;

EPwm4Regs.AQCTLB.bit.CAU = AQ_CLEAR; // Set PWM1A on Zero
EPwm4Regs.AQCTLB.bit.CAD = AQ_SET;

// Define an event (DCAEVT1) based on TZ1 and TZ2
EPwm4Regs.DCTRIPSEL.bit.DCAHCOMPSEL = DC_COMP2OUT; // DCAH = Comparator 2 output
// EPwm4Regs.DCTRIPSEL.bit.DCALCOMPSEL = DC_COMP2OUT; // DCAL = TZ2
EPwm4Regs.TZDCSEL.bit.DCAEVT1 = TZ_DCAH_HI; // DCAEVT1 = DCAH high(will become active as Comparator output goes low)
EPwm4Regs.DCACTL.bit.EVT1SRCSEL = DC_EVT1; // DCAEVT1 = DCAEVT1 (not filtered)
EPwm4Regs.DCACTL.bit.EVT1FRCSYNCSEL = DC_EVT_ASYNC; // Take async path

// Define an event (DCBEVT1) based on TZ1 and TZ2
// EPwm4Regs.DCTRIPSEL.bit.DCBHCOMPSEL = DC_COMP2OUT; // DCBH = Comparator 2 output
// EPwm4Regs.DCTRIPSEL.bit.DCBLCOMPSEL = DC_TZ2; // DCAL = TZ2
// EPwm4Regs.TZDCSEL.bit.DCBEVT1 = TZ_DCBH_LOW; // DCBEVT1 = (will become active as Comparator output goes low)
// EPwm4Regs.DCBCTL.bit.EVT1SRCSEL = DC_EVT1; // DCBEVT1 = DCBEVT1 (not filtered)
// EPwm4Regs.DCBCTL.bit.EVT1FRCSYNCSEL = DC_EVT_ASYNC; // Take async path

// Enable DCAEVT1 and DCBEVT1 are one shot trip sources
// Note: DCxEVT1 events can be defined as one-shot.
// DCxEVT2 events can be defined as cycle-by-cycle.
EPwm4Regs.TZSEL.bit.DCAEVT1 = 1;
// EPwm4Regs.TZSEL.bit.DCBEVT1 = 1;

// What do we want the DCAEVT1 and DCBEVT1 events to do?
// DCAEVTx events can force EPWMxA
// DCBEVTx events can force EPWMxB
EPwm4Regs.TZCTL.bit.TZA = TZ_FORCE_LO; // EPWM4A will go high
// EPwm4Regs.TZCTL.bit.TZA = TZ_NO_CHANGE; // EPWM4A will go high
EPwm4Regs.TZCTL.bit.TZB = TZ_FORCE_LO; // EPWM4B will go low

// Enable TZ interrupt
// EPwm4Regs.TZEINT.bit.OST = 1;
// EPwm2Regs.TZSEL.bit.DCAEVT1 = 1;
EPwm4Regs.TZEINT.bit.DCAEVT1 = 1;
EDIS;


}

void InitComp2(void)
{
EALLOW;
/* Configure AIO4 for CMP2A (analog input) operation*/

GpioCtrlRegs.AIOMUX1.bit.AIO4 = 2;
GpioCtrlRegs.GPAPUD.bit.GPIO3 = 1; // Disable pull-up for GPIO3 (CMP2OUT)
/* Configure Comp pins using GPIO regs*/
// This specifies which of the possible GPIO pins will be Comp functional pins.
// Comment out other unwanted lines.
GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 3; // Configure GPIO3 for CMP2OUT operation
/* Comparator shares the internal BG reference of the ADC,
* must be powered even if ADC is unused.*/
AdcRegs.ADCCTL1.bit.ADCBGPWD = 1;

Comp2Regs.COMPCTL.bit.SYNCSEL = 1; /* asynchronous output */
Comp2Regs.COMPCTL.bit.QUALSEL = 0x000F;

/* Power up Comparator 2 locally */
Comp2Regs.COMPCTL.bit.COMPDACEN = 1;
/* Connect the inverting input to the internal DAC */
Comp2Regs.COMPCTL.bit.COMPSOURCE = 0;
/* Set CMP2 protection threshold */
Comp2Regs.DACVAL.bit.DACVAL = 0x200; //0x200=512

EDIS;

}

谢谢你的回复，我现在设置的是10/1023*3.3,设置成数字量10后，比较器输出还是低电平，那样说明我输入的值比10还小，当我反一下，当DCBEVT1低电平有效时，后我的TZFLAG.DCABVT1标志位会置位的，而我实际输入模拟信号时1.5V，从ADC结果寄存器中是可以读取数据的1600多，所以我判断是我的模拟比较器输入出现了状况。

您下面的代码和我配置应该是一样的，除了你下面的GPIO3和配置成CMP2OUT是什么意思？前面你输入的模拟信号时AIO4 对吧？

还有请问下，DCBH和DCAH在寄存器DCTRIPSEL中选择是怎么选择的，还有AH和AL也是随意选择的吗？

如果是高触发，一般选择AH，如果是低触发，一般选择AL。你可以先看一下，COMPSTS寄存器，比较器是否真的被触发翻转了，如果触发了，说明外部输入电压和DAC没问题。COMP2OUT只是用来把比较器的结果输出到GPIO观测。

您好:

     COMPSTS寄存器确实没有触发，寄存器显示为0，很奇怪，从AD结果寄存器看应该是有电压进去了，实际这个比较器确实没有触发，我的配置我对了好些遍也没发现有错误地方~~AH和BH有区别吗？两个都可以用吧？

您好：

        我还和你一样把compout1的GPIO20口引出来，电平一直是低电平~~

你现在是往哪个口输入电压，用的是哪个比较器？

您好:

    我是用ADCINB2/COMP1B/AIO10引脚作为模拟比较器输入，比较器用的comp1

您好:

     您说的应该是对的，我把ADCIN2B/COMP1B/AIO10当做了COMP1比较器1的输入1A是有问题的，COMP1比较器1的1A应该只能用ADCIN2ACOMP1A/AIO2去复用。

      应该使这个问题，我这边代码把引脚ADCIN2B/COMP1B/AIO10复用成AIO2是有问题的，理解不到位。