/**************************************************************************//**
* [url=home.php?mod=space&uid=288409]@file[/url] main.c
* [url=home.php?mod=space&uid=895143]@version[/url] V1.00
* $Revision: 10 $
* $Date: 18/07/17 6:05p $
* @brief
* Change duty cycle of output waveform to show breathing effect of
Red LED.
*
* SPDX-License-Identifier: Apache-2.0
* Copyright (C) 2018 Nuvoton Technology Corp. All rights reserved.
*
******************************************************************************/
#include <stdio.h>
#include "NuMicro.h"
/*---------------------------------------------------------------------------------------------------------*/
/* Macro, type and constant definitions */
/*---------------------------------------------------------------------------------------------------------*/
#define PWM_Prescaler 48
#define PWM_Period 1999
/*---------------------------------------------------------------------------------------------------------*/
/* Global variables */
/*---------------------------------------------------------------------------------------------------------*/
volatile uint8_t g_u8Forward = 1;
volatile uint32_t g_u32BreathingCount = 0;
void SYS_Init(void)
{
/*---------------------------------------------------------------------------------------------------------*/
/* Init System Clock */
/*---------------------------------------------------------------------------------------------------------*/
/* Enable HIRC clock */
CLK_EnableXtalRC(CLK_PWRCTL_HIRCEN_Msk);
/* Waiting for HIRC clock ready */
CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);
/* Switch HCLK clock source to HIRC and HCLK source divide 1 */
CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));
/* Enable PWM1 module clock */
CLK_EnableModuleClock(PWM1_MODULE);
/*---------------------------------------------------------------------------------------------------------*/
/* PWM clock frequency configuration */
/*---------------------------------------------------------------------------------------------------------*/
/* Set PLL clock as 96 MHz from HIRC/4 */
CLK_EnablePLL(CLK_PLLCTL_PLLSRC_HIRC_DIV4, 96000000);
/* Waiting for PLL clock ready */
CLK_WaitClockReady(CLK_STATUS_PLLSTB_Msk);
/* Select HCLK clock source as PLL and and HCLK clock divider as 2 */
CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_PLL, CLK_CLKDIV0_HCLK(2));
/* PWM clock frequency can be set equal or double to HCLK by choosing case 1 or case 2 */
/* case 1.PWM clock frequency is set equal to HCLK: select PWM module clock source as PCLK */
// CLK_SetModuleClock(PWM1_MODULE, CLK_CLKSEL2_PWM1SEL_PCLK0, 0);
/* case 2.PWM clock frequency is set double to HCLK: select PWM module clock source as PLL */
CLK_SetModuleClock(PWM1_MODULE, CLK_CLKSEL2_PWM1SEL_PLL, NULL);
/*---------------------------------------------------------------------------------------------------------*/
/* Reset PWM1 module */
SYS_ResetModule(PWM1_RST);
/* Update System Core Clock */
SystemCoreClockUpdate();
/*---------------------------------------------------------------------------------------------------------*/
/* Init I/O Multi-function */
/*---------------------------------------------------------------------------------------------------------*/
/* Set PC.4 multi-function pins for PWM1 Channel 1 for Red LED */
SYS->GPC_MFPL = (SYS->GPC_MFPL & (~SYS_GPC_MFPL_PC4MFP_Msk)) |
SYS_GPC_MFPL_PC4MFP_PWM1_CH1;
}
void PWM_Init()
{
/*---------------------------------------------------------------------------------------------------------*/
/* Init PWM1 */
/*---------------------------------------------------------------------------------------------------------*/
/* Set prescaler of PWM1 Channel 1 as PWM_Prescaler for Red LED */
PWM_SET_PRESCALER(PWM1, 1, PWM_Prescaler - 1);
/* Set period of PWM1 Channel 1 as PWM_Period for Red LED */
PWM_SET_CNR(PWM1, 1, PWM_Period);
/* Set compare of PWM1 Channel 1 as 0 for Red LED */
PWM_SET_CMR(PWM1, 1, 0);
/* Set Counter Type */
PWM_SET_ALIGNED_TYPE(PWM1, BIT1, PWM_UP_COUNTER);
/* Set Zero Point Output Low, Compare Up Point Output Nothing, Period Point Output High, Compare Down Point Output High */
PWM_SET_OUTPUT_LEVEL(PWM1, BIT1, PWM_OUTPUT_LOW, PWM_OUTPUT_HIGH, PWM_OUTPUT_NOTHING, PWM_OUTPUT_NOTHING);
/* Enable PWM1 Output path for channel 1 */
PWM_EnableOutput(PWM1, BIT1);
/* Enable PWM1 channel 1 period interrupt */
PWM_EnablePeriodInt(PWM1, 1, 0);
NVIC_EnableIRQ(PWM1_IRQn);
/* Start PWM1 Counter */
PWM_Start(PWM1, BIT1);
}
void PWM1_IRQHandler(void)
{
/* Increase LED brightness */
if(g_u8Forward == 1)
{
if(g_u32BreathingCount < PWM_Period)
g_u32BreathingCount++;
else
g_u8Forward = 0;
}
/* Decrease LED brightness */
else
{
if(g_u32BreathingCount > 0)
g_u32BreathingCount--;
else
g_u8Forward = 1;
}
/* Set compare of PWM1 Channel 1 for Red LED */
PWM_SET_CMR(PWM1, 1, g_u32BreathingCount);
/* Clear PWM1 channel 1 period interrupt flag */
PWM_ClearPeriodIntFlag(PWM1, 1);
}
/*---------------------------------------------------------------------------------------------------------*/
/* Main Function */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void)
{
/* Unlock protected registers */
SYS_UnlockReg();
/* Init System, IP clock and multi-function I/O */
SYS_Init();
/* Lock protected registers */
SYS_LockReg();
/* Init PWM1 to drive RGB LED */
PWM_Init();
while(1);
}
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