32/64 TImer can't enter the interrupt of POS_EDGE

user4178447

#TM-4C123GH6PM

I use the WT0CCP0 to detect the rising edge of PC4, however, Though there is the rising edge, the processor can't enter the interrupt

when I change it to T2CCP1, it works.

WHY the 32/64 timer can't enter the interrupt? Is there any solution ?

over 10 years ago

0 Luis Afonso over 10 years ago

Guru 20670 points

Hi,

If you want a simple rising edge interrupt you can just use a GPIO interrupt

About why the interrupt on the wide timer does not work i am not a medium, or else i would win the lottery. Please provide the code you use to configure the wide timer and the startup.c (in case you configure the handler there)

0 user4178447 over 10 years ago in reply to Luis Afonso

Intellectual 320 points

Thank you .I didn't know about the fantastic GPIO interrupt before. It's really useful

And the code about the interrupt above is

///////////////////////////////////////////////////////

SysCtlPeripher

SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
SYSCTL_XTAL_16MHZ);

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);

alEnable(SYSCTL_PERIPH_WTIMER0);
GPIOPinTypeGPIOInput(GPIO_PORTC_BASE, GPIO_PIN_4);
GPIOPinConfigure(GPIO_PC4_WT0CCP0);
GPIOPinTypeTimer(GPIO_PORTC_BASE, GPIO_PIN_4);
GPIOPadConfigSet(GPIO_PORTC_BASE, GPIO_PIN_4, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD);
TimerConfigure(WTIMER0_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_CAP_TIME);
TimerControlEvent(WTIMER0_BASE, TIMER_A, TIMER_EVENT_POS_EDGE);
TimerLoadSet(WTIMER0_BASE, TIMER_A, 0xffff);
TimerIntRegister(WTIMER0_BASE, TIMER_A, WTimer0AIntHandler);
IntPrioritySet(INT_WTIMER0A, 0<<5);
TimerIntEnable(WTIMER0_BASE, TIMER_CAPA_EVENT);
IntEnable(INT_WTIMER0A);
TimerEnable(WTIMER0_BASE, TIMER_A);

void WTimer0AIntHandler(void)
{
TimerIntClear(WTIMER0_BASE, TimerIntStatus(WTIMER0_BASE, TIMER_CAPA_EVENT));
GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, 0xFF);
BackForth(0);
SysCtlDelay(SysCtlClockGet() / 6);
if(distance(HEAD, PitPos[GOTOPIT_INDEX]) <25);
GOTOPIT_INDEX = GOTOPIT_INDEX == 3 ? 0 : GOTOPIT_INDEX + 1;
}

/////////////////////////////////

In the startup_css.c

///////////

extern void WTimer0AIntHandler(void);

WTimer0AIntHandler, // Wide Timer 0 subtimer A

0 Luis Afonso over 10 years ago in reply to user4178447

Guru 20670 points

Check this out for the digital interrupt: https://sites.google.com/site/luiselectronicprojects/tutorials/tiva-tutorials/tiva-gpio/digital-input-with-interrupt

As for the code i'll have to see it later, as Fourier and his friends are going to make my head jelly for the next hours

0 Petrei over 10 years ago

Guru 26105 points

Hi,

Depending on your configuration, odd or even pins may be used for capture. See the Timer chapter in user manual, there is a description of each timer and each active (possible) pin to use.

@Luis,

Using a GPIO interrupt is not working always - and this is because the interrupt system of Cortex micros. If there are other higher interrupt priorities, these can disturb such implementation, either by latest arrival mechanism or by nesting. The effect is the timer is either triggered, either stopped much later, causing decrease or increase of the measured interval, meaning inconsistent results.

Petrei

0 user4178447 over 10 years ago in reply to Petrei

Intellectual 320 points

however, My code never enter the interrupt instead of sometime

By the way, can you tell me that how can i know which pin that a GPIO interrupt locate in

such as that i configure 1,2,3Pin of Int_GPIOC,when i get into the interrput function, how can i know which pin causes the interrupt?

0 Petrei over 10 years ago in reply to user4178447

Guru 26105 points

Hi,

Actually you have mixed parts of both solutions - it is not going to work as such - suggest to remain consistent with your first request and start by searching this forum, there are some very good examples posted. Please try that.

One word of caution: Port C pins 0..3 are used for JTAG. Do not try to use them otherwise, at least at this stage.

Petrei

0 Luis Afonso over 10 years ago in reply to Petrei

Guru 20670 points

Petrei said:

@Luis,

Using a GPIO interrupt is not working always - and this is because the interrupt system of Cortex micros. If there are other higher interrupt priorities, these can disturb such implementation, either by latest arrival mechanism or by nesting. The effect is the timer is either triggered, either stopped much later, causing decrease or increase of the measured interval, meaning inconsistent results.

Let me see if i understood. You are referring to the priority levels of the GPIO interrupts, which is much lower than the timer interrupts?

Of course the type of interrupt used depends on how precise you need you application.

0 Amit Ashara over 10 years ago in reply to Petrei

TI__Guru**** 244400 points

Hello Petrei,

I agree with your assessment on mixing of solution.

Hello user4178447,

The forum had a code post for the particular mode you mention. And i happen to had the code. May be this will be helpful (not tested it for quite some time now)

Fullscreen 7380.TM4C123_WideTimer_CapTime.c Download

#include <stdint.h>
#include <stdbool.h>
#include "inc/tm4c123gh6pm.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "inc/hw_timer.h"
#include "driverlib/sysctl.h"
#include "driverlib/interrupt.h"
#include "driverlib/gpio.h"
#include "driverlib/timer.h"
#include "driverlib/pin_map.h"

uint32_t period_value;

int main(void)
{
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
    SysCtlDelay(3);

    GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);
    SysCtlDelay(3);

    GPIOPinTypeTimer(GPIO_PORTC_BASE, GPIO_PIN_4);
    GPIOPinConfigure(GPIO_PC4_WT0CCP0);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_WTIMER0);
    SysCtlDelay(3);

    TimerConfigure(WTIMER0_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_CAP_TIME_UP);
    TimerControlEvent(WTIMER0_BASE, TIMER_A, TIMER_EVENT_POS_EDGE);
    TimerIntEnable(WTIMER0_BASE, TIMER_CAPA_EVENT);
    TimerIntClear(WTIMER0_BASE, TIMER_CAPA_EVENT);
    IntEnable(INT_WTIMER0A);
    IntMasterEnable();
    TimerEnable(WTIMER0_BASE, TIMER_A);
    while(1)
    {
    }
}

void WTimer0IntHandler(void)
{
    TimerIntClear(WTIMER0_BASE, TIMER_CAPA_EVENT);
    period_value = TimerValueGet(WTIMER0_BASE, TIMER_A);
    HWREG(WTIMER0_BASE+TIMER_O_TAV) = 0x0;
}

Regards

Amit

0 user4178447 over 10 years ago in reply to Amit Ashara

Intellectual 320 points

Thank you very much, It is really useful

0 user4178447 over 10 years ago in reply to Amit Ashara

Intellectual 320 points

hello Amit Ashara,

there is some codes about HWREG(WTIMER0_BASE+TIMER_O_TAV) = 0x0;

Is there any special thing about the use of HWREG?

In another part of my code, I use HWREG(I2C1_BASE + I2C_O_MCR) |= 0x01;

However the CCS causes error,

#138 expression must be a modifiable lvalue main.c /SENSORtest2 line 685 C/C++ Problem

and warning

function "HWREG" declared implicitly

But I have included the Header files and needed define

#ifndef __HW_TYPES_H__
#define __HW_TYPES_H__ //HWREG

#include<stdint.h>
#include<stdbool.h>
#include"stdio.h"
#include"stdlib.h"
#include"math.h"
#include"inc/hw_memmap.h"
#include"inc/hw_types.h"
#include"inc/hw_ints.h"
#include"inc/hw_i2c.h"
#include"driverlib/gpio.h"
#include"driverlib/pin_map.h"
#include"driverlib/pwm.h"
#include"driverlib/sysctl.h"
#include"driverlib/uart.h"
#include"driverlib/timer.h"
#include"driverlib/interrupt.h"
#include"driverlib/i2c.h"

Can you tell me where the problem is ? How to correct it?

0 Amit Ashara over 10 years ago in reply to user4178447

TI__Guru**** 244400 points

Hello user4178447

HWREG is a macro to access a memory location (can be a peripheral register) and is defined in hw_types.h

Regarding the error, can you check the line of code mentioned in the error (or paste a snapshot of the same)

Also remove

#ifndef __HW_TYPES_H__
#define __HW_TYPES_H__ //HWREG

and change

#include"inc/hw_memmap.h"
#include"inc/hw_types.h"

#include"inc/hw_types.h"
#include"inc/hw_memmap.h"

Regards

Amit

0 user4178447 over 10 years ago in reply to Amit Ashara

Intellectual 320 points

Just at the point.

When I exchange the position of two header files, error disappeared.

Thank you

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32/64 TImer can't enter the interrupt of POS_EDGE