CC1354P10: Setting up PinMux for Input Edge Time mode

Satya Raji

Part Number: CC1354P10
Other Parts Discussed in Thread: SYSCONFIG,

Tool/software:

Hello E2E,

I was trying to implement Edge Time capture on a GPIO pin. My intension is to capture the time between two edges on a GPIO pin.

When I try to implement using GPTimerCC26XX.h. Somehow, I don't see any definition/reference for "PINCC26XX_setMux". Below is my sample code...

GPTimerCC26XX_Handle capTimer;
GPTimerCC26XX_Params tParams;
GPTimerCC26XX_Params_init(&tParams);

tParams.width = GPT_CONFIG_16BIT;
tParams.mode = GPT_MODE_EDGE_TIME;
tParams.direction = GPTimerCC26XX_DIRECTION_UP;
tParams.debugStallMode = GPTimerCC26XX_DEBUG_STALL_OFF;

capTimer = GPTimerCC26XX_open(GPT_A, &tParams);

if(capTimer == NULL) {
Log_error0("Failed to open GPTimer");
Task_exit();
while(1);
}

GPTimerCC26XX_setCaptureEdge(capTimer, GPTimerCC26XX_BOTH_EDGES);
GPTimerCC26XX_registerInterrupt(capTimer, captureTimerCallback, GPT_INT_CAPTURE);

GPTimerCC26XX_start(capTimer);

Appreciate your help in sorting this out.

Regards,

Satya

10 months ago

0 Siri 9 months ago

TI__Guru* 84631 points

Hi Satya

You need to ise the PINCC26XX_setMux(); instead of the PINCC26XX_setMux, since the pin driver is not longer supported.

Siri

0 Satya Raji 9 months ago in reply to Siri

Prodigy 130 points

I tried using PINCC26XX_setMux();. I guess no where it was defined. Can you please elaborate a little more.

Regards,

Satya

0 Siri 9 months ago in reply to Satya Raji

TI__Guru* 84631 points

Sorry, typo on my end.

I meant to say that you should use GPIO_setConfigAndMux instead of PINCC26XX_setMux();

Siri

0 Satya Raji 9 months ago in reply to Siri

Prodigy 130 points

Hi Siri,

The capture pin configuration is working good now. Thanks for that.

But again the counter reading the same value all the time, irrespective of the input pulse width. I can see the ISR calling with the correct timing. But when I try to read the counter value using the following code...

GPTimerCC26XX_setCaptureEdge(capTimer, GPTimerCC26XX_NEG_EDGE);
GPTimerCC26XX_registerInterrupt(capTimer, captureTimerCallback, GPT_INT_CAPTURE);

GPIO_setConfigAndMux(GPIO_USS_ECHO, GPIO_CFG_INPUT, GPT_PIN_0A);
GPTimerCC26XX_start(capTimer);

void captureTimerCallback(GPTimerCC26XX_Handle handle, GPTimerCC26XX_IntMask interruptMask) {GPIO_toggle(GPIO_USS_N);
/*In input edge time, this register contains the timer value at which the last edge event took place*/
captureValue = GPTimerCC26XX_getValue(capTimer);

ussTriggerFlag = 0xFF;
}

Appreciate your help. Regards

0 Siri 9 months ago in reply to Satya Raji

TI__Guru* 84631 points

Can you please take the empty example from the SDK and implement a small demo code of what you are doing exactly in your code, so that I can test the same thing here?

Send me the modified e,pty.c file and your sysConfig file, and I can use that in my empty example.

the example should run on a LaunchPad

Siri

0 Siri 9 months ago in reply to Siri

TI__Guru* 84631 points

I made the simple code below and where able to read the timer values as expected:

#include <unistd.h>
#include <stdint.h>
#include <stddef.h>

/* Driver Header files */
#include <ti/drivers/GPIO.h>
#include <ti/drivers/timer/GPTimerCC26XX.h>

#include "ti_drivers_config.h"

GPTimerCC26XX_Handle hTimer;
GPTimerCC26XX_Params timerParams;

uint32_t edgeCount_1 = 0;
uint32_t edgeCount_2 = 0;
bool edge1 = true;

void buttonCallbackFunction(uint_least8_t index) {

    // Simple debounce logic
    CPUdelay((uint32_t)((48000000/3)*0.050f));
    GPIO_toggle(CONFIG_GPIO_LED_GREEN);
}

void timerCallback(GPTimerCC26XX_Handle handle, GPTimerCC26XX_IntMask interruptMask)
{

    GPIO_write(CONFIG_GPIO_LED_RED, 1);
    if (edge1)
    {
        edgeCount_1 = GPTimerCC26XX_getValue(handle);
        edge1 = false;
    }
    else
    {
        edgeCount_2 = GPTimerCC26XX_getValue(handle);
        edge1 = true;
    }
    GPIO_write(CONFIG_GPIO_LED_RED, 0);
}

void *mainThread(void *arg0)
{
    GPIO_init();

    // Toggle the RLED the BTN-1 toggles (pushed and released)
    // RLED is connected to the input CONFIG_GPIO_EDGE_INPUT (DIO0) which is connected to the GPTimer
    GPIO_setConfig(CONFIG_GPIO_BTN1, GPIO_CFG_IN_PU | GPIO_CFG_IN_INT_BOTH_EDGES);
    GPIO_setCallback(CONFIG_GPIO_BTN1, buttonCallbackFunction);
    GPIO_enableInt(CONFIG_GPIO_BTN1);

    GPTimerCC26XX_Params_init(&timerParams);
    timerParams.mode = GPT_MODE_EDGE_TIME;
    timerParams.width = GPT_CONFIG_16BIT;
    timerParams.direction = GPTimerCC26XX_DIRECTION_UP;
    timerParams.debugStallMode = GPTimerCC26XX_DEBUG_STALL_OFF;

    hTimer = GPTimerCC26XX_open(CONFIG_GPTIMER_0, &timerParams);

    GPTimerCC26XX_registerInterrupt(hTimer, timerCallback, GPT_INT_CAPTURE);

    GPTimerCC26XX_PinMux pinMux = GPTimerCC26XX_getPinMux(hTimer);

    GPIO_setConfigAndMux(CONFIG_GPIO_EDGE_INPUT,(GPIO_CFG_INPUT_INTERNAL | GPIO_CFG_PULL_NONE_INTERNAL), pinMux);

    GPTimerCC26XX_setCaptureEdge(hTimer, GPTimerCC26XX_BOTH_EDGES);

    GPTimerCC26XX_start(hTimer);
    while (1);
}

0 Satya Raji 9 months ago in reply to Siri

Prodigy 130 points

Hi Siri,

My application also does the same as your example code except in the ISR section, where I was only counting for one edge. Now I copied your example, as per my understanding this code should store timer values for rise and fall edges into the variables edgeCount_1 and edgeCount_2.

I supplied my capture pin with a 1mSec on/off timing pulse, I am seeing some random count values. It supposed to give 48000-1 every time, since I am using a 48MHz (using Ti's CC1354P10_1 evaluation board). I understand the timer should automatically goes to zero after an ISR executed by the the Capture pin. Which I don't see in the real time. Please help me if I miss anything.

Further, can you please help me with the pre-scaler setup for the same timer. Appreciate your help.

Regards,

Satya Raji

0 Siri 9 months ago in reply to Satya Raji

TI__Guru* 84631 points

The timer is not restarting/going to zero after it has capture an event.

The timer counts from 0 to 0xFFFF and then starts from 0 again.

Counting from 0 to 0xFFFF at 48 mHz only takes 1.36 ms

When you are trying to measure a pulse that is 1 ms wide, you will only get the correct value (48000) when both edgeCount_1 and edgeCount_2 has been captured during the same "count period"

If you run the code below, you will see that diff = 48000, when making sure that edgeCount_1 < edgeCount_2.

void timerCallback(GPTimerCC26XX_Handle handle, GPTimerCC26XX_IntMask interruptMask)
{
    if (edge1)
    {
        edgeCount_1 = GPTimerCC26XX_getValue(handle);
        edge1 = false;
    }
    else
    {
        edgeCount_2 = GPTimerCC26XX_getValue(handle);
        edge1 = true;

        if(edgeCount_1 < edgeCount_2)
        {
            diff = edgeCount_2 - edgeCount_1;
        }
    }
}

void *mainThread(void *arg0)
{
    GPIO_init();

    GPTimerCC26XX_Params_init(&timerParams);
    timerParams.mode = GPT_MODE_EDGE_TIME;
    timerParams.width = GPT_CONFIG_16BIT;
    timerParams.direction = GPTimerCC26XX_DIRECTION_UP;
    timerParams.debugStallMode = GPTimerCC26XX_DEBUG_STALL_OFF;

    hTimer = GPTimerCC26XX_open(CONFIG_GPTIMER_0, &timerParams);

    GPTimerCC26XX_registerInterrupt(hTimer, timerCallback, GPT_INT_CAPTURE);

    GPTimerCC26XX_PinMux pinMux = GPTimerCC26XX_getPinMux(hTimer);

    GPIO_setConfigAndMux(CONFIG_GPIO_EDGE_INPUT,(GPIO_CFG_INPUT_INTERNAL | GPIO_CFG_PULL_NONE_INTERNAL), pinMux);

    GPTimerCC26XX_setCaptureEdge(hTimer, GPTimerCC26XX_BOTH_EDGES);

    GPTimerCC26XX_start(hTimer);
    while (1);
}

Siri

0 Satya Raji 9 months ago in reply to Siri

Prodigy 130 points

Hi Siri,

Thanks for your help. I was supplying a pulse more than 2mSec width, which essentially 16-it timer was overflowing results wrong count on my variable. Sorted now. Trying to use the pre-scaler, somehow I am missing some APIs and related documentation. I have the TRM, but there is a big gap between the stack and the TRM. Can you please help me in that, setting up the pre scaler? Regards.

Satya Raji

+1 Siri 9 months ago in reply to Satya Raji

TI__Guru* 84631 points

You need to use GPTimerCC26XX_setLoadValue to write to the TAPR register.

You can see how it is accessed/used in GPTimerCC26XX.c

/*!
 *  @brief  Shared code to be used by GPTimerCC26XX_setLoadValue / GPTimerCC26XX_setMatchValue
 *          Sets load/match values using input value and register offset for
 *          prescaler and load/match register
 *          Functions calling this should specifiy which the register offset
 *          within the module base to the corresponding timer A register.
 */
static void GPTimerCC26XXSetLoadMatch(GPTimerCC26XX_Handle handle,
                                      GPTimerCC26XX_Value loadMatchVal,
                                      uint32_t regPre,
                                      uint32_t regLoadMatch)
{
    /* Get the pointer to the object and hwAttrs */
    GPTimerCC26XX_HWAttrs const *hwAttrs = handle->hwAttrs;
    GPTimerCC26XX_Object *object         = handle->object;
    uint32_t offset                      = GPT_LUT[handle->timerPart].offset;

    /* Split value into correct timer and prescaler register for 16 bit modes. */
    if (object->width == GPT_CONFIG_16BIT)
    {
        /* Upper byte is used by prescaler */
        uint8_t prescaleValue = 0xFF & (loadMatchVal >> 16);
        /* Discard upper byte (24 bits max) */
        loadMatchVal &= 0xFFFF;

        /* Set prescale value */
        HWREG(hwAttrs->baseAddr + offset + regPre) = prescaleValue;
    }

    /* Set load / match value */
    HWREG(hwAttrs->baseAddr + offset + regLoadMatch) = loadMatchVal;
}

/*!
 *  @brief  Set GPTimer load value. For 32-bit configuration all 32 bits can
 *          be used. For split mode / 16-bit mode maximum value is 24 bits.
 *          Function concatenates prescaler functionality automatically
 */
void GPTimerCC26XX_setLoadValue(GPTimerCC26XX_Handle handle, GPTimerCC26XX_Value loadValue)
{
    GPTimerCC26XXSetLoadMatch(handle, loadValue, GPT_O_TAPR, GPT_O_TAILR);
}

Siri

+1 Satya Raji 9 months ago in reply to Siri

Prodigy 130 points

Thanks for your continuous support.

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CC1354P10: Setting up PinMux for Input Edge Time mode