text: /****************************************************************************
   * @file     main.c
   * @version  V3.0
   * $Revision: 6 $
   * $Date: 15/05/22 2:01p $
   * @brief    Demonstrate A/D conversion with burst mode.
   *           In burst mode, ADC will sample and convert a specified channel continuously and
   *           store the conversion result in FIFO buffers.
   *
   * @note
   * Copyright (C) 2014 Nuvoton Technology Corp. All rights reserved.
   *
   ******************************************************************************/
  #include <stdio.h>
  #include "M051Series.h"
  
  #define PLLCON_SETTING  CLK_PLLCON_50MHz_HXT
  #define PLL_CLOCK       50000000
  
  
  /*---------------------------------------------------------------------------------------------------------*/
  /* Define Function Prototypes                                                                              */
  /*---------------------------------------------------------------------------------------------------------*/
  void SYS_Init(void);
  void UART0_Init(void);
  void AdcBurstModeTest(void);
  
  
  /*---------------------------------------------------------------------------------------------------------*/
  /* Define global variables and constants                                                                   */
  /*---------------------------------------------------------------------------------------------------------*/
  #define BURST_COUNT 20
  volatile uint32_t g_u32AdcDataCount;
  uint16_t g_au16AdcData[BURST_COUNT];
  
  
  void SYS_Init(void)
  {
      /*---------------------------------------------------------------------------------------------------------*/
      /* Init System Clock                                                                                       */
      /*---------------------------------------------------------------------------------------------------------*/
  
      /* Enable Internal RC 22.1184MHz clock */
      CLK->PWRCON |= CLK_PWRCON_OSC22M_EN_Msk;
  
      /* Waiting for Internal RC clock ready */
      while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_OSC22M_STB_Msk));
  
      /* Switch HCLK clock source to Internal RC */
      CLK->CLKSEL0 &= ~CLK_CLKSEL0_HCLK_S_Msk;
      CLK->CLKSEL0 |= CLK_CLKSEL0_HCLK_S_HIRC;
  
      /* Enable external XTAL 12MHz clock */
      CLK->PWRCON |= CLK_PWRCON_XTL12M_EN_Msk;
  
      /* Waiting for external XTAL clock ready */
      while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_XTL12M_STB_Msk));
  
      /* Set core clock as PLL_CLOCK from PLL */
      CLK->PLLCON = PLLCON_SETTING;
      while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_PLL_STB_Msk));
      CLK->CLKSEL0 &= (~CLK_CLKSEL0_HCLK_S_Msk);
      CLK->CLKSEL0 |= CLK_CLKSEL0_HCLK_S_PLL;
  
      /* Update System Core Clock */
      /* User can use SystemCoreClockUpdate() to calculate PllClock, SystemCoreClock and CycylesPerUs automatically. */
      //SystemCoreClockUpdate();
      PllClock        = PLL_CLOCK;            // PLL
      SystemCoreClock = PLL_CLOCK / 1;        // HCLK
      CyclesPerUs     = PLL_CLOCK / 1000000;  // For SYS_SysTickDelay()
  
      /* Enable UART module clock */
      CLK->APBCLK |= CLK_APBCLK_UART0_EN_Msk;
  
      /* Enable ADC module clock */
      CLK->APBCLK |= CLK_APBCLK_ADC_EN_Msk ;
  
      /* Select UART module clock source */
      CLK->CLKSEL1 &= ~CLK_CLKSEL1_UART_S_Msk;
      CLK->CLKSEL1 |= CLK_CLKSEL1_UART_S_HXT;
  
      /* Select ADC module clock source */
      CLK->CLKSEL1 &= ~CLK_CLKSEL1_ADC_S_Msk ;
      CLK->CLKSEL1 |= CLK_CLKSEL1_ADC_S_HIRC ;
  
      /* ADC clock source is 22.1184MHz, set divider to 7, ADC clock is 22.1184/7 MHz */
      CLK->CLKDIV  = (CLK->CLKDIV & ~CLK_CLKDIV_ADC_N_Msk) | (((7) - 1) << CLK_CLKDIV_ADC_N_Pos);
  
  
      /*---------------------------------------------------------------------------------------------------------*/
      /* Init I/O Multi-function                                                                                 */
      /*---------------------------------------------------------------------------------------------------------*/
  
      /* Set P3 multi-function pins for UART0 RXD and TXD */
      SYS->P3_MFP &= ~(SYS_MFP_P30_Msk | SYS_MFP_P31_Msk);
      SYS->P3_MFP |= (SYS_MFP_P30_RXD0 | SYS_MFP_P31_TXD0);
  
      /* Disable the P1.0 - P1.3 digital input path to avoid the leakage current. */
      P1->OFFD = 0xF << GPIO_OFFD_OFFD_Pos;
      /* Configure the P1.0 - P1.3 ADC analog input pins */
      SYS->P1_MFP &= ~(SYS_MFP_P10_Msk | SYS_MFP_P11_Msk | SYS_MFP_P12_Msk | SYS_MFP_P13_Msk);
      SYS->P1_MFP |= SYS_MFP_P10_AIN0 | SYS_MFP_P11_AIN1 | SYS_MFP_P12_AIN2 | SYS_MFP_P13_AIN3 ;
  
  }
  
  /*---------------------------------------------------------------------------------------------------------*/
  /* Init UART                                                                                               */
  /*---------------------------------------------------------------------------------------------------------*/
  void UART0_Init()
  {
      /* Reset UART IP */
      SYS->IPRSTC2 |=  SYS_IPRSTC2_UART0_RST_Msk;
      SYS->IPRSTC2 &= ~SYS_IPRSTC2_UART0_RST_Msk;
  
      /* Configure UART0 and set UART0 Baudrate */
      UART0->BAUD = UART_BAUD_MODE2 | UART_BAUD_MODE2_DIVIDER(__HXT, 115200);
      UART0->LCR = UART_WORD_LEN_8 | UART_PARITY_NONE | UART_STOP_BIT_1;
  }
  
  /*---------------------------------------------------------------------------------------------------------*/
  /* Function: ADC_GetConversionRate                                                                         */
  /*                                                                                                         */
  /* Parameters:                                                                                             */
  /*   None.                                                                                                 */
  /*                                                                                                         */
  /* Returns:                                                                                                */
  /*      Return the A/D conversion rate (sample/second)                                                     */
  /*                                                                                                         */
  /* Description:                                                                                            */
  /*   The conversion rate depends on the clock source of ADC clock.                                         */
  /*   It only needs 21 ADC clocks to complete an A/D conversion.                                            */
  /*---------------------------------------------------------------------------------------------------------*/
  static __INLINE uint32_t ADC_GetConversionRate()
  {
      uint32_t u32AdcClkSrcSel;
      uint32_t u32ClkTbl[4] = {__HXT, 0, 0, __HIRC};
  
      /* Set the PLL clock frequency */
      u32ClkTbl[1] = PllClock;
      /* Set the system core clock frequency */
      u32ClkTbl[2] = SystemCoreClock;
      /* Get the clock source setting */
      u32AdcClkSrcSel = ((CLK->CLKSEL1 & CLK_CLKSEL1_ADC_S_Msk) >> CLK_CLKSEL1_ADC_S_Pos);
      /* Return the ADC conversion rate */
      return ((u32ClkTbl[u32AdcClkSrcSel]) / (((CLK->CLKDIV & CLK_CLKDIV_ADC_N_Msk) >> CLK_CLKDIV_ADC_N_Pos) + 1) / 21);
  }
  
  /*---------------------------------------------------------------------------------------------------------*/
  /* Function: AdcBurstModeTest                                                                              */
  /*                                                                                                         */
  /* Parameters:                                                                                             */
  /*   None.                                                                                                 */
  /*                                                                                                         */
  /* Returns:                                                                                                */
  /*   None.                                                                                                 */
  /*                                                                                                         */
  /* Description:                                                                                            */
  /*   ADC burst mode test.                                                                                  */
  /*---------------------------------------------------------------------------------------------------------*/
  void AdcBurstModeTest()
  {
      uint8_t  u8Option;
      uint32_t u32Count;
  
      printf("\n\nConversion rate: %d samples/second\n", ADC_GetConversionRate());
      printf("\n");
      printf("+----------------------------------------------------------------------+\n");
      printf("|                      ADC burst mode sample code                      |\n");
      printf("+----------------------------------------------------------------------+\n");
      printf("\nIn this test, software will get %d conversion results from the specified channel.\n", BURST_COUNT);
  
      while(1)
      {
          printf("\nSelect input mode:\n");
          printf("  [1] Single end input (channel 2 only)\n");
          printf("  [2] Differential input (channel pair 1 only)\n");
          printf("  Other keys: exit burst mode test\n");
          u8Option = getchar();
          if(u8Option == '1')
          {
              printf("%d conversion results of channel 2:\n", BURST_COUNT);
              /* Set the ADC operation mode as burst, input mode as single-end and enable the ADC converter */
              ADC->ADCR = (ADC_ADCR_ADMD_BURST | ADC_ADCR_DIFFEN_SINGLE_END | ADC_ADCR_ADEN_CONVERTER_ENABLE);
              /* Enable analog input channel 2 */
              ADC->ADCHER |= ((ADC->ADCHER & ~ADC_ADCHER_CHEN_Msk) | (1 << 2));
  
              /* clear the A/D interrupt flag for safe */
              ADC->ADSR = ADC_ADSR_ADF_Msk;
  
              /* Enable the ADC interrupt */
              ADC->ADCR |= ADC_ADCR_ADIE_Msk;
              NVIC_EnableIRQ(ADC_IRQn);
  
              /* Reset the ADC data counter and start A/D conversion */
              g_u32AdcDataCount = 0;
              ADC->ADCR |= ADC_ADCR_ADST_Msk;
  
              while(g_u32AdcDataCount < BURST_COUNT);
  
              /* Stop A/D conversion */
              ADC->ADCR &= ~ADC_ADCR_ADST_Msk;
  
              /* Disable the ADC interrupt */
              ADC->ADCR &= ~ADC_ADCR_ADIE_Msk;
          }
          else if(u8Option == '2')
          {
              printf("%d conversion results of differential input channel pair 1:\n", BURST_COUNT);
              /* Set the ADC operation mode as burst, input mode as differential and enable the ADC converter */
              ADC->ADCR = (ADC_ADCR_ADMD_BURST | ADC_ADCR_DIFFEN_DIFFERENTIAL | ADC_ADCR_ADEN_CONVERTER_ENABLE);
              /* Enable analog input channel 2 for differential input channel pair 1 */
              ADC->ADCHER |= ((ADC->ADCHER & ~ADC_ADCHER_CHEN_Msk) | (1 << 2));
  
              /* clear the A/D interrupt flag for safe */
              ADC->ADSR = ADC_ADSR_ADF_Msk;
  
              /* Enable the ADC interrupt */
              ADC->ADCR |= ADC_ADCR_ADIE_Msk;
              NVIC_EnableIRQ(ADC_IRQn);
  
              /* Reset the ADC data counter and start A/D conversion */
              g_u32AdcDataCount = 0;
              ADC->ADCR |= ADC_ADCR_ADST_Msk;
  
              while(g_u32AdcDataCount < BURST_COUNT);
  
              /* Stop A/D conversion */
              ADC->ADCR &= ~ADC_ADCR_ADST_Msk;
  
              /* Disable the ADC interrupt */
              ADC->ADCR &= ~ADC_ADCR_ADIE_Msk;
          }
          else
              return ;
  
          for(u32Count = 0; u32Count < BURST_COUNT; u32Count++)
          {
              printf("Conversion result: 0x%X\n", g_au16AdcData[u32Count]);
          }
  
          /* Change operation mode to clear burst mode FIFO buffers */
          ADC->ADCR &= ADC_ADCR_ADMD_Msk;
  
      }
  }
  
  
  /*---------------------------------------------------------------------------------------------------------*/
  /* ADC interrupt handler                                                                                   */
  /*---------------------------------------------------------------------------------------------------------*/
  void ADC_IRQHandler(void)
  {
      while(((ADC->ADSR & (1 << ((0) + ADC_ADSR_VALID_Pos))) ? 1 : 0)) /* Check the VALID bits */
      {
          if(g_u32AdcDataCount >= BURST_COUNT)
              return;
          /* In burst mode, the software always gets the conversion result of the specified channel from channel 0 */
          g_au16AdcData[g_u32AdcDataCount++] = (uint16_t)((ADC->ADDR[(0)] & ADC_ADDR_RSLT_Msk) >> ADC_ADDR_RSLT_Pos);
      }
      ADC->ADSR = ADC_ADSR_ADF_Msk;      /* clear the A/D conversion flag */
  }
  
  
  /*---------------------------------------------------------------------------------------------------------*/
  /* MAIN function                                                                                           */
  /*---------------------------------------------------------------------------------------------------------*/
  main(void)
  {
  
      /* Unlock protected registers */
      SYS->REGWRPROT = 0x59;
      SYS->REGWRPROT = 0x16;
      SYS->REGWRPROT = 0x88;
  
      /* Init System, IP clock and multi-function I/O */
      SYS_Init();
  
      /* Lock protected registers */
      SYS->REGWRPROT = 0x0;
  
      /* Init UART0 for printf */
      UART0_Init();
  
      /*---------------------------------------------------------------------------------------------------------*/
      /* SAMPLE CODE                                                                                             */
      /*---------------------------------------------------------------------------------------------------------*/
  
      printf("\nSystem clock rate: %d Hz", SystemCoreClock);
  
      /* Burst Mode test */
      AdcBurstModeTest();
  
      /* Reset ADC module */
      SYS->IPRSTC2 |= (1 << SYS_IPRSTC2_ADC_RST_Pos) ;
      SYS->IPRSTC2 &= ~(1 << (SYS_IPRSTC2_ADC_RST_Pos)) ;
  
      /* Disable ADC IP clock */
      CLK->APBCLK &= ~CLK_APBCLK_ADC_EN_Msk;
  
      /* Disable External Interrupt */
      NVIC_DisableIRQ(ADC_IRQn);
  
      printf("Exit ADC sample code\n");
  
      while(1);
  
  }
  
  