CRC的单片机应用

/**************************************************************************//**

 * [url=home.php?mod=space&uid=288409]@file[/url]     main.c

 * [url=home.php?mod=space&uid=895143]@version[/url]  V1.00

 * $Revision: 2 $

 * $Date: 15/04/13 10:05a $

 * [url=home.php?mod=space&uid=247401]@brief[/url]    Implement CRC in CRC-8 mode and get the CRC checksum result.

 * @note

 * Copyright (C) 2011 Nuvoton Technology Corp. All rights reserved.

 ******************************************************************************/

#include <stdio.h>

#include <string.h>

#include "NUC100Series.h"



#define PLL_CLOCK           50000000





void SYS_Init(void)

{

    /*---------------------------------------------------------------------------------------------------------*/

    /* Init System Clock                                                                                       */

    /*---------------------------------------------------------------------------------------------------------*/

    /* Enable Internal RC 22.1184MHz 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 12MHz clock */

    CLK_EnableXtalRC(CLK_PWRCON_XTL12M_EN_Msk);



    /* Waiting for 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);    

    

    /* Select UART module clock source */

    CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART_S_HXT, CLK_CLKDIV_UART(1));

    

    /* Enable PDMA module clock for CRC operation */

    CLK_EnableModuleClock(PDMA_MODULE);    



    /*---------------------------------------------------------------------------------------------------------*/

    /* Init I/O Multi-function                                                                                 */

    /*---------------------------------------------------------------------------------------------------------*/

    /* Set PB multi-function pins for UART0 RXD, TXD */

    SYS->GPB_MFP = SYS_GPB_MFP_PB0_UART0_RXD | SYS_GPB_MFP_PB1_UART0_TXD;

}



void UART0_Init(void)

{

    /*---------------------------------------------------------------------------------------------------------*/

    /* Init UART                                                                                               */

    /*---------------------------------------------------------------------------------------------------------*/

    /* Reset UART0 */

    SYS_ResetModule(UART0_RST);



    /* Configure UART0 and set UART0 Baudrate */

    UART_Open(UART0, 115200);

}



/*---------------------------------------------------------------------------------------------------------*/

/*  MAIN function                                                                                          */

/*---------------------------------------------------------------------------------------------------------*/

int main(void)

{

    const uint8_t acCRCSrcPattern[] = "123456789";

    uint32_t i, u32TargetChecksum = 0x58, u32CalChecksum = 0;

    uint8_t *p8SrcAddr;



    /* 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();



    printf("\n\nCPU [url=home.php?mod=space&uid=72445]@[/url] %dHz\n", SystemCoreClock);

    printf("+---------------------------------+\n");

    printf("|    CRC CRC-8 Mode Sample Code   |\n");

    printf("+---------------------------------+\n\n");



    printf("# Calculate string \"123456789\" CRC-8 checksum value by CRC CPU mode.\n");

    printf("    - Seed value is 0x5A            \n");

    printf("    - CPU Write Length is 8-bit     \n");

    printf("    - Checksum Complement disable   \n");

    printf("    - Checksum Reverse disable      \n");

    printf("    - Write Data Complement disable \n");

    printf("    - Write Data Reverse disable    \n");

    printf("    - Checksum should be 0x%X       \n\n", u32TargetChecksum);



    /* Set CRC source buffer address for CRC-8 CPU mode */

    p8SrcAddr = (uint8_t *)acCRCSrcPattern;



    /* Configure CRC operation settings for CRC-8 CPU mode */

    CRC_Open(CRC_8, 0, 0x5A, CRC_CPU_WDATA_8);



    /* Start to execute CRC-8 CPU operation */

    for(i = 0; i < strlen((char *)acCRCSrcPattern); i++)

    {

        CRC_WRITE_DATA((p8SrcAddr[i] & 0xFF));

    }



    /* Get CRC-8 checksum value */

    u32CalChecksum = CRC_GetChecksum();

    printf("CRC checksum is 0x%X ... %s.\n", u32CalChecksum, (u32CalChecksum == u32TargetChecksum) ? "PASS" : "FAIL");



    /* Disable CRC function */

    CRC->CTL &= ~CRC_CTL_CRCCEN_Msk;



    while(1);

}



/*** (C) COPYRIGHT 2013 Nuvoton Technology Corp. ***/