- /****************************************************************************
- * [url=home.php?mod=space&uid=288409]@file[/url] main.c
- * [url=home.php?mod=space&uid=895143]@version[/url] V3.0
- * $Revision: 1 $
- * $Date: 16/06/29 4:40p $
- * [url=home.php?mod=space&uid=247401]@brief[/url] Measure AVDD voltage by ADC.
- * @note
- * Copyright (C) 2014 Nuvoton Technology Corp. All rights reserved.
- *
- ******************************************************************************/
- #include <stdio.h>
- #include "M058S.h"
- #define PLL_CLOCK 50000000
- #define VBG_VOLTAGE (1200) /* 1.20V = 1200 mV (Typical band-gap voltage of M058S series) */
- #define ADC_SAMPLE_COUNT 128 /* The last line of GetAVDDCodeByADC() need revise when ADC_SAMPLE_COUNT is changed. */
- /* For example, if ADC_SAMPLE_COUNT is changed to 64, then the code need revised to "return (u32Sum >> 6);" */
- /*---------------------------------------------------------------------------------------------------------*/
- /* Define Function Prototypes */
- /*---------------------------------------------------------------------------------------------------------*/
- void SYS_Init(void);
- void UART0_Init(void);
- void AdcMeasureAVDD(void);
- uint32_t GetAVDDCodeByADC(void);
- uint32_t GetAVDDVoltage(void);
- /*---------------------------------------------------------------------------------------------------------*/
- /* Define global variables and constants */
- /*---------------------------------------------------------------------------------------------------------*/
- volatile uint8_t g_u8ADF;
- void SYS_Init(void)
- {
- /*---------------------------------------------------------------------------------------------------------*/
- /* Init System Clock */
- /*---------------------------------------------------------------------------------------------------------*/
- /* Enable Internal RC 22.1184 MHz clock */
- CLK_EnableXtalRC(CLK_PWRCON_OSC22M_EN_Msk);
- /* Waiting for Internal RC clock ready */
- CLK_WaitClockReady(CLK_CLKSTATUS_OSC22M_STB_Msk);
- /* Switch HCLK clock source to Internal RC and HCLK source divide 1 */
- CLK_SetHCLK(CLK_CLKSEL0_HCLK_S_HIRC, CLK_CLKDIV_HCLK(1));
- /* Enable external XTAL 12 MHz clock */
- CLK_EnableXtalRC(CLK_PWRCON_XTL12M_EN_Msk);
- /* Waiting for external XTAL clock ready */
- CLK_WaitClockReady(CLK_CLKSTATUS_XTL12M_STB_Msk);
- /* Set core clock as PLL_CLOCK from PLL */
- CLK_SetCoreClock(PLL_CLOCK);
- /* Enable UART module clock */
- CLK_EnableModuleClock(UART0_MODULE);
- /* Enable ADC module clock */
- CLK_EnableModuleClock(ADC_MODULE);
- /* Select UART module clock source */
- CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART_S_PLL, CLK_CLKDIV_UART(1));
- /* ADC clock source is 22.1184 MHz, set divider to 7, ADC clock is 22.1184/7 MHz */
- CLK_SetModuleClock(ADC_MODULE, CLK_CLKSEL1_ADC_S_HIRC, CLK_CLKDIV_ADC(7));
- /*---------------------------------------------------------------------------------------------------------*/
- /* 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_RXD | SYS_MFP_P31_TXD;
- /* Disable the P1.0 - P1.3 digital input path to avoid the leakage current */
- GPIO_DISABLE_DIGITAL_PATH(P1, 0xF);
- /* 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 IP */
- SYS_ResetModule(UART0_RST);
- /* Configure UART0 and set UART0 Baudrate */
- UART_Open(UART0, 115200);
- }
- /*---------------------------------------------------------------------------------------------------------*/
- /* ADC interrupt handler */
- /*---------------------------------------------------------------------------------------------------------*/
- void ADC_IRQHandler(void)
- {
- uint32_t u32Flag;
- /* Get ADC conversion finish interrupt flag */
- u32Flag = ADC_GET_INT_FLAG(ADC, ADC_ADF_INT);
- /* Check ADC conversion finish */
- if(u32Flag & ADC_ADF_INT)
- g_u8ADF = 1;
- /* Clear conversion finish flag */
- ADC_CLR_INT_FLAG(ADC, u32Flag);
- }
- /*---------------------------------------------------------------------------------------------------------*/
- /* Function: GetAVDDVoltage */
- /* */
- /* Parameters: */
- /* None. */
- /* */
- /* Returns: */
- /* AVDD voltage(mV). */
- /* */
- /* Description: */
- /* Use Band-gap voltage to calculate AVDD voltage */
- /*---------------------------------------------------------------------------------------------------------*/
- uint32_t GetAVDDVoltage(void)
- {
- uint32_t u32ConversionResult;
- uint64_t u64MvAVDD;
- /* Calculate Vref by using conversion result of VBG */
- u32ConversionResult = GetAVDDCodeByADC();
- /* u32ConversionResult = VBG * 4096 / Vref, Vref = AVDD */
- /* => AVDD = VBG * 4096 / u32ConversionResult */
- u64MvAVDD = (VBG_VOLTAGE << 12) / (uint64_t)u32ConversionResult;
- printf("Conversion result: 0x%X\n", u32ConversionResult);
- return (uint32_t)u64MvAVDD;
- }
- /*---------------------------------------------------------------------------------------------------------*/
- /* Function: GetAVDDCodeByADC */
- /* */
- /* Parameters: */
- /* None. */
- /* */
- /* Returns: */
- /* ADC code of AVDD voltage. */
- /* */
- /* Description: */
- /* Get ADC conversion result of Band-gap voltage. */
- /*---------------------------------------------------------------------------------------------------------*/
- uint32_t GetAVDDCodeByADC(void)
- {
- uint32_t u32Count, u32Sum, u32Data;
- /* Power on ADC */
- ADC_POWER_ON(ADC);
- /* Configure ADC: single-end input, single scan mode, enable ADC analog circuit. */
- ADC_Open(ADC, ADC_ADCR_DIFFEN_SINGLE_END, ADC_ADCR_ADMD_SINGLE, BIT7);
- /* Configure the analog input source of channel 7 as internal band-gap voltage */
- ADC_CONFIG_CH7(ADC, ADC_ADCHER_PRESEL_INT_BANDGAP);
- /* Clear conversion finish flag */
- ADC_CLR_INT_FLAG(ADC, ADC_ADF_INT);
- /* Enable ADC conversion finish interrupt */
- ADC_EnableInt(ADC, ADC_ADF_INT);
- NVIC_EnableIRQ(ADC_IRQn);
- g_u8ADF = 0;
- u32Sum = 0;
- /* sample times are according to ADC_SAMPLE_COUNT definition */
- for(u32Count = 0; u32Count < ADC_SAMPLE_COUNT; u32Count++)
- {
- /* Delay for band-gap voltage stability */
- CLK_SysTickDelay(100);
- /* Start A/D conversion */
- ADC_START_CONV(ADC);
- u32Data = 0;
- /* Wait conversion done */
- while(g_u8ADF == 0);
- g_u8ADF = 0;
- /* Get the conversion result */
- u32Data = ADC_GET_CONVERSION_DATA(ADC, 7);
- /* Sum each conversion data */
- u32Sum += u32Data;
- }
- /* Disable ADC interrupt */
- ADC_DisableInt(ADC, ADC_ADF_INT);
- /* Disable ADC */
- ADC_POWER_DOWN(ADC);
- /* Return the average of ADC_SAMPLE_COUNT samples */
- return (u32Sum >> 7);
- }
- /*---------------------------------------------------------------------------------------------------------*/
- /* MAIN function */
- /*---------------------------------------------------------------------------------------------------------*/
- int main(void)
- {
- uint32_t u32AVDDVoltage;
- /* Unlock protected registers */
- SYS_UnlockReg();
- /* Init System, IP clock and multi-function I/O */
- SYS_Init();
- /* Lock protected registers */
- SYS_LockReg();
- /* Init UART0 for printf */
- UART0_Init();
- /*---------------------------------------------------------------------------------------------------------*/
- /* SAMPLE CODE */
- /*---------------------------------------------------------------------------------------------------------*/
- printf("\nSystem clock rate: %d Hz\n", SystemCoreClock);
- printf("+----------------------------------------------------------------------+\n");
- printf("| ADC for AVDD Measurement sample code |\n");
- printf("+----------------------------------------------------------------------+\n");
- printf("\nIn this sample code, software will get voltage value from AVDD.\n");
- printf("Notice that the Vref of ADC is from AVDD.\n\n");
- /*------------------------------------------------------------------------------------------------------------------
- The method of measured AVDD voltage is using ADC to get conversion result of band-gap voltage.
- For example, the typical value of band-gap voltage is 1.20 V, and Vref of ADC is from AVDD.
- Through getting ADC conversion result of band-gap voltage, then AVDD voltage can be calculated by below formula:
- ConversionResult = VBG * 4096 / Vref, Vref = AVDD and VBG = 1.20V
- => AVDD = 1.20V * 4096 / ConversionResult
- Note 1 : The measured AVDD has deviation that causes by the band-gap voltage has deviation in different temperature, power voltage and ADC conversion deviation.(4 LSB)
- The deviation of measured AVDD is list as follows:
- The Spec. of band-gap voltage in M058S is as follows:
- -----------------------------------------------------------------------------------------
- | | Min. | Typ. | Max. | |
- | |--------------------------- VDD = 2.5 V ~ 5.5 V |
- | band-gap voltage | 1.14 V | 1.20 V | 1.26 V | temperature = -40 ~ 85 degrees Celsius |
- | | | | | |
- -----------------------------------------------------------------------------------------
- Deviation range of measured AVDD
- ----------------------------------------------------
- | | Min. Deviation | Max. Deviation |
- | | | |
- | | VBG = 1.14 V | VBG = 1.26 V |
- |--------------------------------------------------|
- | AVDD = 2.5 V | -5.71% | 5.80% |
- |--------------------------------------------------|
- | AVDD = 5.5 V | -6.56% | 6.79% |
- ----------------------------------------------------
- Note 2: In this sample code is using the typical value of M058S series: 1.20 V, and it can be modified by VBG_VOLTAGE definition.
- ------------------------------------------------------------------------------------------------------------------*/
- /* Measure AVDD */
- u32AVDDVoltage = GetAVDDVoltage();
- printf("AVDD Voltage: %dmV\n", u32AVDDVoltage);
- /* Disable ADC module */
- ADC_Close(ADC);
- /* Disable ADC IP clock */
- CLK_DisableModuleClock(ADC_MODULE);
- /* Disable External Interrupt */
- NVIC_DisableIRQ(ADC_IRQn);
- printf("\nExit ADC sample code\n");
- while(1);
- }
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