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/*
* Copyright (c) 2015, Freescale Semiconductor, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice, this list
* of conditions and the following disclaimer.
*
* o Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* o Neither the name of Freescale Semiconductor, Inc. nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "gpt.h"
#include "board.h"
#include "clock_freq.h"
#include "debug_console_imx.h"
/* This case will run for 5 seconds */
static volatile uint32_t num = 10;
static uint32_t counterA, counterB;
int main(void)
{
uint32_t freqA, freqB;
gpt_mode_config_t config = {
.freeRun = false,
.waitEnable = true,
.stopEnable = true,
.dozeEnable = true,
.dbgEnable = false,
.enableMode = true
};
hardware_init();
/* Initialize GPT module */
GPT_Init(BOARD_GPTA_BASEADDR, &config);
GPT_Init(BOARD_GPTB_BASEADDR, &config);
/* Set GPT clock source, when use OSC as clock source, we need to make sure the OSC freq
* after divided by OscPrescaler should be less than half of the peripheral clock set by
* CCM */
GPT_SetClockSource(BOARD_GPTA_BASEADDR, gptClockSourceOsc);
GPT_SetClockSource(BOARD_GPTB_BASEADDR, gptClockSourcePeriph);
/* Divide GPTA osc clock source frequency by 2, and divide additional 2 inside GPT module */
GPT_SetOscPrescaler(BOARD_GPTA_BASEADDR, 1);
GPT_SetPrescaler(BOARD_GPTA_BASEADDR, 1);
/* Divide GPTB clock source frequency by 2 inside GPT module */
GPT_SetPrescaler(BOARD_GPTB_BASEADDR, 1);
/* Get GPT clock frequency */
freqA = 24000000 / 2; /* A is bound to OSC directly, with OSC divider 2 */
freqB = get_gpt_clock_freq(BOARD_GPTB_BASEADDR); /* Get B peripheral clock freq */
/* GPTA and GPTB frequency is divided by 2 inside module */
freqA /= 2;
freqB /= 2;
/* Set both GPT modules to 1 second duration */
GPT_SetOutputCompareValue(BOARD_GPTA_BASEADDR, gptOutputCompareChannel1, freqA);
GPT_SetOutputCompareValue(BOARD_GPTB_BASEADDR, gptOutputCompareChannel1, freqB);
/* Set GPT interrupt priority to same value to avoid handler preemption */
NVIC_SetPriority(BOARD_GPTA_IRQ_NUM, 3);
NVIC_SetPriority(BOARD_GPTB_IRQ_NUM, 3);
/* Enable NVIC interrupt */
NVIC_EnableIRQ(BOARD_GPTA_IRQ_NUM);
NVIC_EnableIRQ(BOARD_GPTB_IRQ_NUM);
/* Enable GPT Output Compare1 interrupt */
GPT_SetIntCmd(BOARD_GPTA_BASEADDR, gptStatusFlagOutputCompare1, true);
GPT_SetIntCmd(BOARD_GPTB_BASEADDR, gptStatusFlagOutputCompare1, true);
PRINTF("GPT timer will now start\n\r");
PRINTF("counter/freq ratio should be close to 0.0 or 1.0 ...\n\r");
/* GPT start */
GPT_Enable(BOARD_GPTA_BASEADDR);
GPT_Enable(BOARD_GPTB_BASEADDR);
while (true)
{
__WFI();
while ((num & 1) != 0); /* wait both timer handled */
PRINTF("\tGPT A freq %u, counter %u.\n\r", freqA, counterA);
PRINTF("\tGPT B freq %u, counter %u.\n\r", freqB, counterB);
if (num == 0)
{
/* Stop GPT */
GPT_Disable(BOARD_GPTA_BASEADDR);
GPT_Disable(BOARD_GPTB_BASEADDR);
PRINTF("GPT example finished...\n\r");
}
}
}
void BOARD_GPTA_HANDLER()
{
GPT_ClearStatusFlag(BOARD_GPTA_BASEADDR, gptStatusFlagOutputCompare1);
if (num && --num)
counterB = GPT_ReadCounter(BOARD_GPTB_BASEADDR);
}
void BOARD_GPTB_HANDLER()
{
GPT_ClearStatusFlag(BOARD_GPTB_BASEADDR, gptStatusFlagOutputCompare1);
if (num && --num)
counterA = GPT_ReadCounter(BOARD_GPTA_BASEADDR);
}
/*******************************************************************************
* EOF
******************************************************************************/
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