/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 2 $
 * $Date: 16/10/25 4:28p $
 * @brief
 *           Show how to use auto baud rate detection function.
 *           This sample code needs to work with USCI_UART_AutoBaudRate_Master.
 * @note
 * @copyright SPDX-License-Identifier: Apache-2.0
 *
 * @copyright Copyright (C) 2016 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include "stdio.h"
#include "NUC126.h"


#define PLLCTL_SETTING  CLK_PLLCTL_72MHz_HXT
#define PLL_CLOCK       72000000


/*---------------------------------------------------------------------------------------------------------*/
/* Define functions prototype                                                                              */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void);
extern char GetChar(void);
void USCI_AutoBaudRate_RxTest(void);


void SYS_Init(void)
{

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Enable HIRC clock (Internal RC 22.1184MHz) */
    CLK->PWRCTL |= CLK_PWRCTL_HIRCEN_Msk;

    /* Wait for HIRC clock ready */
    while(!(CLK->STATUS & CLK_STATUS_HIRCSTB_Msk));

    /* Select HCLK clock source as HIRC and HCLK clock divider as 1 */
    CLK->CLKSEL0 = (CLK->CLKSEL0 & (~CLK_CLKSEL0_HCLKSEL_Msk)) | CLK_CLKSEL0_HCLKSEL_HIRC;
    CLK->CLKDIV0 = (CLK->CLKDIV0 & (~CLK_CLKDIV0_HCLKDIV_Msk)) | CLK_CLKDIV0_HCLK(1);

    /* Set PLL to Power-down mode */
    CLK->PLLCTL |= CLK_PLLCTL_PD_Msk;

    /* Enable HXT clock (external XTAL 12MHz) */
    CLK->PWRCTL |= CLK_PWRCTL_HXTEN_Msk;

    /* Wait for HXT clock ready */
    while(!(CLK->STATUS & CLK_STATUS_HXTSTB_Msk));

    /* Set core clock as PLL_CLOCK from PLL */
    CLK->PLLCTL = PLLCTL_SETTING;
    while(!(CLK->STATUS & CLK_STATUS_PLLSTB_Msk));
    CLK->CLKSEL0 = (CLK->CLKSEL0 & (~CLK_CLKSEL0_HCLKSEL_Msk)) | CLK_CLKSEL0_HCLKSEL_PLL;

    /* Update System Core Clock */
    PllClock        = PLL_CLOCK;            // PLL
    SystemCoreClock = PLL_CLOCK / 1;        // HCLK
    CyclesPerUs     = PLL_CLOCK / 1000000;  // For CLK_SysTickDelay()

    /* Enable UART and USCI module clock */
    CLK->APBCLK0 |= CLK_APBCLK0_UART0CKEN_Msk;
    CLK->APBCLK1 |= CLK_APBCLK1_USCI0CKEN_Msk;

    /* Select UART module clock source as HIRC and UART module clock divider as 1 */
    CLK->CLKSEL1 = (CLK->CLKSEL1 & (~CLK_CLKSEL1_UARTSEL_Msk)) | CLK_CLKSEL1_UARTSEL_HIRC;
    CLK->CLKDIV0 = (CLK->CLKDIV0 & (~CLK_CLKDIV0_UARTDIV_Msk)) | CLK_CLKDIV0_UART(1);

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Set PD multi-function pins for UART0 RXD(PD.0) and TXD(PD.1) */
    SYS->GPD_MFPL = (SYS->GPD_MFPL & (~SYS_GPD_MFPL_PD0MFP_Msk)) | SYS_GPD_MFPL_PD0MFP_UART0_RXD;
    SYS->GPD_MFPL = (SYS->GPD_MFPL & (~SYS_GPD_MFPL_PD1MFP_Msk)) | SYS_GPD_MFPL_PD1MFP_UART0_TXD;

    /* Set PC multi-function pins for USCI0_DAT0(PC.0), USCI0_DAT1(PC.1) */
    SYS->GPC_MFPL = (SYS->GPC_MFPL & (~SYS_GPC_MFPL_PC0MFP_Msk)) | SYS_GPC_MFPL_PC0MFP_USCI0_DAT0;
    SYS->GPC_MFPL = (SYS->GPC_MFPL & (~SYS_GPC_MFPL_PC1MFP_Msk)) | SYS_GPC_MFPL_PC1MFP_USCI0_DAT1;

}


void UART0_Init()
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART0 */
    SYS->IPRST1 |=  SYS_IPRST1_UART0RST_Msk;
    SYS->IPRST1 &= ~SYS_IPRST1_UART0RST_Msk;

    /* Configure UART0 and set UART0 baud rate */
    UART0->BAUD = UART_BAUD_MODE2 | UART_BAUD_MODE2_DIVIDER(__HIRC, 115200);
    UART0->LINE = UART_WORD_LEN_8 | UART_PARITY_NONE | UART_STOP_BIT_1;
}

void USCI0_Init()
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init USCI                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset USCI0 */
    SYS->IPRST2 |=  SYS_IPRST2_USCI0RST_Msk;
    SYS->IPRST2 &= ~SYS_IPRST2_USCI0RST_Msk;

    /* Configure USCI0 as UART mode */
    UUART0->CTL = (2 << UUART_CTL_FUNMODE_Pos);                                 /* Set UART function mode */
    UUART0->LINECTL = UUART_WORD_LEN_8 | UUART_LINECTL_LSB_Msk;                 /* Set UART line configuration */
    UUART0->DATIN0 = (2 << UUART_DATIN0_EDGEDET_Pos);                           /* Set falling edge detection */
    UUART0->BRGEN = (103 << UUART_BRGEN_CLKDIV_Pos) | (5 << UUART_BRGEN_DSCNT_Pos); /* Set UART baud rate as 115200bps */
    UUART0->PROTCTL |= UUART_PROTCTL_PROTEN_Msk;                                /* Enable UART protocol */
}

/*---------------------------------------------------------------------------------------------------------*/
/*  Main Function                                                                                          */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void)
{

    /* Unlock protected registers */
    SYS_UnlockReg();

    /* Init System, peripheral clock and multi-function I/O */
    SYS_Init();

    /* Lock protected registers */
    SYS_LockReg();

    /* Init UART0 for printf */
    UART0_Init();

    /* Init USCI0 for test */
    USCI0_Init();

    /*---------------------------------------------------------------------------------------------------------*/
    /* SAMPLE CODE                                                                                             */
    /*---------------------------------------------------------------------------------------------------------*/

    printf("\n\nCPU @ %d Hz\n", SystemCoreClock);

    printf("\nUSCI UART Sample Program\n");

    /* USCI UART auto baud rate sample master function */
    USCI_AutoBaudRate_RxTest();

    while(1);

}

/*---------------------------------------------------------------------------------------------------------*/
/*  Get UUART Baud Rate Function                                                                           */
/*---------------------------------------------------------------------------------------------------------*/
uint32_t GetUuartBaudrate(UUART_T *uuart)
{
    uint32_t u32PCLKFreq, u32PDSCnt, u32DSCnt, u32ClkDiv;

    /* Get PCLK frequency */
    SystemCoreClockUpdate();

    if((uuart == UUART0) || (uuart == UUART2))
    {
        if(CLK->CLKSEL0 & CLK_CLKSEL0_PCLK0SEL_Msk)
            u32PCLKFreq = SystemCoreClock >> 1;
        else
            u32PCLKFreq = SystemCoreClock;
    }
    else
    {
        if(CLK->CLKSEL0 & CLK_CLKSEL0_PCLK1SEL_Msk)
            u32PCLKFreq = SystemCoreClock >> 1;
        else
            u32PCLKFreq = SystemCoreClock;
    }

    /* Get pre-divider counter */
    u32PDSCnt = ((uuart->BRGEN & UUART_BRGEN_PDSCNT_Msk) >> UUART_BRGEN_PDSCNT_Pos);

    /* Get denominator counter */
    u32DSCnt = ((uuart->BRGEN & UUART_BRGEN_DSCNT_Msk) >> UUART_BRGEN_DSCNT_Pos);

    /* Get clock divider */
    u32ClkDiv = ((uuart->BRGEN & UUART_BRGEN_CLKDIV_Msk) >> UUART_BRGEN_CLKDIV_Pos);

    return (u32PCLKFreq / (u32PDSCnt + 1) / (u32DSCnt + 1) / (u32ClkDiv + 1));
}

/*---------------------------------------------------------------------------------------------------------*/
/*  Auto Baud Rate Function Rx Test                                                                        */
/*---------------------------------------------------------------------------------------------------------*/
void USCI_AutoBaudRate_RxTest()
{

    printf("\n");
    printf("+-----------------------------------------------------------+\n");
    printf("|     Pin Configure                                         |\n");
    printf("+-----------------------------------------------------------+\n");
    printf("|  ______                                            _____  |\n");
    printf("| |      |                                          |     | |\n");
    printf("| |Master|                                          |Slave| |\n");
    printf("| |    TX|--USCI0_DAT1(PC.1) <==> USCI0_DAT0(PC.0)--|RX   | |\n");
    printf("| |______|                                          |_____| |\n");
    printf("|                                                           |\n");
    printf("+-----------------------------------------------------------+\n");

    printf("\n");
    printf("+-----------------------------------------------------------+\n");
    printf("|     Auto Baud Rate Function Test (Slave)                  |\n");
    printf("+-----------------------------------------------------------+\n");
    printf("|  Description :                                            |\n");
    printf("|    The sample code needs two boards. One is Master and    |\n");
    printf("|    the other is slave.  Master will send input pattern    |\n");
    printf("|    0x55 with different baud rate. It can check if Slave   |\n");
    printf("|    calculates correct baud rate.                          |\n");
    printf("+-----------------------------------------------------------+\n");

    /* Set CLKDIV=DSCNT=0x5, Timing Measurement Counter Enable and Timing Measurement Counter Clock Source */
    UUART0->BRGEN = ((0x5 << UUART_BRGEN_CLKDIV_Pos) | (0x5 << UUART_BRGEN_DSCNT_Pos) | (UUART_BRGEN_TMCNTEN_Msk) | (UUART_BRGEN_TMCNTSRC_Msk));

    /* Enable auto baud rate detect function */
    UUART0->PROTCTL |= UUART_PROTCTL_ABREN_Msk;

    printf("\nreceiving input pattern... ");

    /* Wait until auto baud rate detect finished or time-out */
    while(UUART0->PROTCTL & UUART_PROTCTL_ABREN_Msk);

    if(UUART0->PROTSTS & UUART_PROTSTS_ABRDETIF_Msk)
    {
        /* Clear auto baud rate detect finished flag */
        UUART0->PROTSTS = UUART_PROTSTS_ABRDETIF_Msk;
        printf("Baud rate is %dbps.\n", GetUuartBaudrate(UUART0));
    }
    else if(UUART0->PROTSTS & UUART_PROTSTS_ABERRSTS_Msk)
    {
        /* Clear auto baud rate detect time-out flag */
        UUART0->PROTSTS = UUART_PROTSTS_ABERRSTS_Msk;
        printf("Error!\n");
    }

    printf("\nUSCI UART Sample Code End.\n");

}
