/*****************************************************************************
 * Copyright (c) 2022, Nations Technologies 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:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Nations' name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY NATIONS "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL NATIONS BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
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/**
 * @file main.c
 * @author Nations 
 * @version V2.0.0
 *
 * @copyright Copyright (c) 2022, Nations Technologies Inc. All rights reserved.
 */
#include "main.h"
#include <stdio.h>
#include <stdint.h>
#include "n32l43x.h"
#include "log.h"
#include "n32l43x_rcc.h"
#include "User_Sysclock_Config.h"
#include "User_Key_Config.h"


/** @addtogroup LP_SLEEP
 * @{
 */



/**
 * @brief  Delay function.
 *     @arg nCount
 */
void delay(vu32 nCount)
{
    vu32 index = 0;
    for (index = (34000 * nCount); index != 0; index--)
    {
    }
}

/**
 * @brief  set system clock with MSI.
 * @param void.
 */
void SetSysClock_MSI(void)
{
    if(RESET == RCC_GetFlagStatus(RCC_CTRLSTS_FLAG_MSIRD))
    {
       /* Enable MSI and Config Clock */
       RCC_ConfigMsi(RCC_MSI_ENABLE, RCC_MSI_RANGE_4M);
       /* Waits for MSI start-up */
       while(SUCCESS != RCC_WaitMsiStable());
    }
    /* Enable Prefetch Buffer */
    FLASH_PrefetchBufSet(FLASH_PrefetchBuf_EN);
    /* Select MSI as system clock source */
    RCC_ConfigSysclk(RCC_SYSCLK_SRC_MSI);
    /* Wait till MSI is used as system clock source */
    while (RCC_GetSysclkSrc() != 0x00)
    {
        /* If this bits are always not set,
        it means system clock select MSI failed,
        user can add here some code to deal with this error */
    }

    /* HCLK = SYSCLK */
    RCC_ConfigHclk(RCC_SYSCLK_DIV1);
    /* PCLK2 = HCLK */
    RCC_ConfigPclk2(RCC_HCLK_DIV1);
    /* PCLK1 = HCLK */
    RCC_ConfigPclk1(RCC_HCLK_DIV1);
}

/**
 * @brief  Main program.
 */
int main(void)
{
    /*!< At this stage the microcontroller clock setting is already configured,
         this is done through SystemInit() function which is called from startup
         file (startup_n32l43x_xx.s) before to branch to application main.
         To reconfigure the default setting of SystemInit() function, refer to
         system_n32l43x.c file
       */
    /* Initialize USART,TX: PA9 RX: PA10*/
    log_init(); 
    /* Enable PWR Clock */
    RCC_EnableAPB1PeriphClk(RCC_APB1_PERIPH_PWR, ENABLE);
      /* Initialize key button interrupt to wakeup LP SLEEP mode*/
    KeyInputExtiInit(KEY_INPUT_PORT, KEY_INPUT_PIN);
      /* Clear the EXIT Interrupt flag */
    EXTI_ClrITPendBit(EXTI_LINE0);

    while (1)
    {
        /* Insert a long delay */
        delay(1000);
        log_info("\r\n MCU Prepare Enter LP Sleep Mode Core Stop Run \r\n");
        
        /* Before entering LP RUN mode, you must make sure that the system clock is less
        than or equal to 4MHz. This project takes configuring MSI (4MHz) as an example, 
        and users can configure other clock sources as system clock as needed */
        SetSysClock_MSI();
        
        /* Request to enter LP SLEEP mode*/
        PWR_EnterLowPowerSleepMode(SLEEP_OFF_EXIT, PWR_SLEEPENTRY_WFE);
        /* MCU wakeup from LP SLEEP mode by interrupt and goto the LP RUN mode */
        delay(10);
        /* Exit LP RUN mode*/
        PWR_ExitLowPowerRunMode();
        /* Switch sysclok from MSI to PLL */
        SetSysClockToPLL(108000000,SYSCLK_PLLSRC_HSE_PLLDIV2);
        log_info("\r\n MCU Run In Run Mode Sysclock From PLL(108MHz) \r\n");
    }
}


