GD32F450_BMC_BaseCode/app/bmc/AuthChip/CM_RDCKSUM.c

// Read Checksum
//

// CryptoMemory Library Include Files
#include "CM_LIB.h"
#include "CM_I2C.h"
#include "CM_I2C_L.h"
#include "CM_GPA.h"

uint8_t	ucCmdRdChk[4] = {0xb6, 0x02, 0x00, 0x02};

// Read Checksum
uint8_t cm_ReadChecksum(uint8_t * pucChkSum)
{
    uint8_t ucDCR[1];
	uint8_t ucReturn;

    // 20 0x00s (10 0x00s, ignore first byte, 5 0x00s, ignore second byte, 5 0x00s  
    cm_GPAGenN(20);
	  
    // Read the checksum                  
    if((ucReturn = cm_ReadCommand(ucCmdRdChk, pucChkSum, 2))!= SUCCESS) return ucReturn;
	
    // Check if unlimited reads allowed
    if ((ucReturn = cm_ReadConfigZone(DCR_ADDR, ucDCR, 1)) != SUCCESS) return ucReturn;
    if ((ucDCR[0]&DCR_UCR)) cm_ResetCrypto();
	
    return SUCCESS;
}