28235等硬件定时器太少，不够用！-TI中文支持网

只有三个硬件定时器，如果使用SYS/BIOS就被占了一个，如果使用PWM做控制，至少有占掉1个，如果代码还需要更精确的硬件定时，例如us级别的有要占用一个，再想干点别的，就没有硬件定时器了。

Forrest：

楼主可以考虑用PWM模块的timer来当定时器用。

具体的楼主可以参考TI例程包中的Example_2833xEPwmTimerInt例程。

decai wang：

回复 Forrest:

// TI File $Revision: /main/2 $// Checkin $Date: July 30, 2009 18:44:34 $//###########################################################################//// FILE: Example_2833xEPwmTimerInt.c//// TITLE: DSP2833x ePWM Timer Interrupt example.//// ASSUMPTIONS://// This program requires the DSP2833x header files.//// Other then boot mode configuration, no other hardware configuration// is required.//// As supplied, this project is configured for "boot to SARAM"// operation. The 2833x Boot Mode table is shown below.// For information on configuring the boot mode of an eZdsp,// please refer to the documentation included with the eZdsp,//// $Boot_Table://// GPIO87 GPIO86 GPIO85 GPIO84// XA15 XA14 XA13 XA12// PU PU PU PU// ==========================================// 1 1 1 1 Jump to Flash// 1 1 1 0 SCI-A boot// 1 1 0 1 SPI-A boot// 1 1 0 0 I2C-A boot// 1 0 1 1 eCAN-A boot// 1 0 1 0 McBSP-A boot// 1 0 0 1 Jump to XINTF x16// 1 0 0 0 Jump to XINTF x32// 0 1 1 1 Jump to OTP// 0 1 1 0 Parallel GPIO I/O boot// 0 1 0 1 Parallel XINTF boot// 0 1 0 0 Jump to SARAM <- "boot to SARAM"// 0 0 1 1 Branch to check boot mode// 0 0 1 0 Boot to flash, bypass ADC cal// 0 0 0 1 Boot to SARAM, bypass ADC cal// 0 0 0 0 Boot to SCI-A, bypass ADC cal// Boot_Table_End$//// DESCRIPTION://// This example configures the ePWM Timers and increments// a counter each time an interrupt is taken.//// As supplied://// All ePWM's are initalized. Note that not all devices in the 2833x// family have all 6 ePWMs.//// All timers have the same period// The timers are started sync'ed// An interrupt is taken on a zero event for each ePWM timer//// ePWM1: takes an interrupt every event// ePWM2: takes an interrupt every 2nd event// ePWM3: takes an interrupt every 3rd event// ePWM4-ePWM6: take an interrupt every event//// Thus the Interrupt count for ePWM1, ePWM4-ePWM6 should be equal// The interrupt count for ePWM2 should be about half that of ePWM1// and the interrupt count for ePWM3 should be about 1/3 that of ePWM1//// Watch Variables:// EPwm1TimerIntCount// EPwm2TimerIntCount// EPwm3TimerIntCount// EPwm4TimerIntCount// EPwm5TimerIntCount// EPwm6TimerIntCount////###########################################################################// $TI Release: 2833x/2823x Header Files V1.32 $// $Release Date: June 28, 2010 $//###########################################################################

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

// Configure which ePWM timer interrupts are enabled at the PIE level:// 1 = enabled, 0 = disabled#define PWM1_INT_ENABLE 1#define PWM2_INT_ENABLE 1#define PWM3_INT_ENABLE 1#define PWM4_INT_ENABLE 1#define PWM5_INT_ENABLE 1#define PWM6_INT_ENABLE 1

// Configure the period for each timer#define PWM1_TIMER_TBPRD 0x1FFF#define PWM2_TIMER_TBPRD 0x1FFF#define PWM3_TIMER_TBPRD 0x1FFF#define PWM4_TIMER_TBPRD 0x1FFF#define PWM5_TIMER_TBPRD 0x1FFF#define PWM6_TIMER_TBPRD 0x1FFF

// Prototype statements for functions found within this file.interrupt void epwm1_timer_isr(void);interrupt void epwm2_timer_isr(void);interrupt void epwm3_timer_isr(void);interrupt void epwm4_timer_isr(void);interrupt void epwm5_timer_isr(void);interrupt void epwm6_timer_isr(void);void InitEPwmTimer(void);

// Global variables used in this exampleUint32 EPwm1TimerIntCount;Uint32 EPwm2TimerIntCount;Uint32 EPwm3TimerIntCount;Uint32 EPwm4TimerIntCount;Uint32 EPwm5TimerIntCount;Uint32 EPwm6TimerIntCount;

void main(void){ int i;

// Step 1. Initialize System Control:// PLL, WatchDog, enable Peripheral Clocks// This example function is found in the DSP2833x_SysCtrl.c file. InitSysCtrl();

// Step 2. Initalize GPIO:// This example function is found in the DSP2833x_Gpio.c file and// illustrates how to set the GPIO to it's default state.// InitGpio(); // Skipped for this example

// 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 DSP2833x_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 DSP2833x_DefaultIsr.c.// This function is found in DSP2833x_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.EPWM1_INT = &epwm1_timer_isr; PieVectTable.EPWM2_INT = &epwm2_timer_isr; PieVectTable.EPWM3_INT = &epwm3_timer_isr; PieVectTable.EPWM4_INT = &epwm4_timer_isr; PieVectTable.EPWM5_INT = &epwm5_timer_isr; PieVectTable.EPWM6_INT = &epwm6_timer_isr; EDIS; // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:// This function is found in DSP2833x_InitPeripherals.c// InitPeripherals(); // Not required for this example InitEPwmTimer(); // For this example, only initialize the ePWM Timers

// Step 5. User specific code, enable interrupts:

// Initalize counters: EPwm1TimerIntCount = 0; EPwm2TimerIntCount = 0; EPwm3TimerIntCount = 0; EPwm4TimerIntCount = 0; EPwm5TimerIntCount = 0; EPwm6TimerIntCount = 0;

// Enable CPU INT3 which is connected to EPWM1-6 INT: IER |= M_INT3;

// Enable EPWM INTn in the PIE: Group 3 interrupt 1-6 PieCtrlRegs.PIEIER3.bit.INTx1 = PWM1_INT_ENABLE; PieCtrlRegs.PIEIER3.bit.INTx2 = PWM2_INT_ENABLE; PieCtrlRegs.PIEIER3.bit.INTx3 = PWM3_INT_ENABLE; PieCtrlRegs.PIEIER3.bit.INTx4 = PWM4_INT_ENABLE; PieCtrlRegs.PIEIER3.bit.INTx5 = PWM5_INT_ENABLE; PieCtrlRegs.PIEIER3.bit.INTx6 = PWM6_INT_ENABLE;

// 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"); for(i=1;i<=10;i++) {} }

}

void InitEPwmTimer(){

EALLOW; SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0; // Stop all the TB clocks EDIS;

// Setup Sync EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // Pass through EPwm2Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // Pass through EPwm3Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // Pass through EPwm4Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // Pass through EPwm5Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // Pass through EPwm6Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // Pass through

// Allow each timer to be sync'ed

EPwm1Regs.TBCTL.bit.PHSEN = TB_ENABLE; EPwm2Regs.TBCTL.bit.PHSEN = TB_ENABLE; EPwm3Regs.TBCTL.bit.PHSEN = TB_ENABLE; EPwm4Regs.TBCTL.bit.PHSEN = TB_ENABLE; EPwm5Regs.TBCTL.bit.PHSEN = TB_ENABLE; EPwm6Regs.TBCTL.bit.PHSEN = TB_ENABLE;

EPwm1Regs.TBPHS.half.TBPHS = 100; EPwm2Regs.TBPHS.half.TBPHS = 200; EPwm3Regs.TBPHS.half.TBPHS = 300; EPwm4Regs.TBPHS.half.TBPHS = 400; EPwm5Regs.TBPHS.half.TBPHS = 500; EPwm6Regs.TBPHS.half.TBPHS = 600;

EPwm1Regs.TBPRD = PWM1_TIMER_TBPRD; EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Count up EPwm1Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Select INT on Zero event EPwm1Regs.ETSEL.bit.INTEN = PWM1_INT_ENABLE; // Enable INT EPwm1Regs.ETPS.bit.INTPRD = ET_1ST; // Generate INT on 1st event

EPwm2Regs.TBPRD = PWM2_TIMER_TBPRD; EPwm2Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Count up EPwm2Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Enable INT on Zero event EPwm2Regs.ETSEL.bit.INTEN = PWM2_INT_ENABLE; // Enable INT EPwm2Regs.ETPS.bit.INTPRD = ET_2ND; // Generate INT on 2nd event

EPwm3Regs.TBPRD = PWM3_TIMER_TBPRD; EPwm3Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Count up EPwm3Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Enable INT on Zero event EPwm3Regs.ETSEL.bit.INTEN = PWM3_INT_ENABLE; // Enable INT EPwm3Regs.ETPS.bit.INTPRD = ET_3RD; // Generate INT on 3rd event

EPwm4Regs.TBPRD = PWM4_TIMER_TBPRD; EPwm4Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Count up EPwm4Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Enable INT on Zero event EPwm4Regs.ETSEL.bit.INTEN = PWM4_INT_ENABLE; // Enable INT EPwm4Regs.ETPS.bit.INTPRD = ET_1ST; // Generate INT on 1st event

EPwm5Regs.TBPRD = PWM5_TIMER_TBPRD; EPwm5Regs.TBCTL.bit.CTRMODE= TB_COUNT_UP; // Count up EPwm5Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Enable INT on Zero event EPwm5Regs.ETSEL.bit.INTEN = PWM5_INT_ENABLE; // Enable INT EPwm5Regs.ETPS.bit.INTPRD = ET_1ST; // Generate INT on 1st event

EPwm6Regs.TBPRD = PWM6_TIMER_TBPRD; EPwm6Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Count up EPwm6Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Enable INT on Zero event EPwm6Regs.ETSEL.bit.INTEN = PWM6_INT_ENABLE; // Enable INT EPwm6Regs.ETPS.bit.INTPRD = ET_1ST; // Generate INT on 1st event

EALLOW; SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1; // Start all the timers synced EDIS;

}

// Interrupt routines uses in this example:interrupt void epwm1_timer_isr(void){ EPwm1TimerIntCount++;

// Clear INT flag for this timer EPwm1Regs.ETCLR.bit.INT = 1;