GD32F450_BMC_BaseCode/app/bmc/AuthChip/CM_SWRUSER.c

// Write Small User Zone
//
// The Write Small User Zone function is used to write data to CryptoMemory devices that have
// 256 bytes or less in each user zone (AT88SC3216C, and smaller)

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

// Write Small User Zone
uint8_t cm_WriteSmallZone(uint8_t  ucCryptoAddr, uint8_t* pucBuffer, uint8_t ucCount)
{
	uint8_t ucReturn;
	
	ucCM_InsBuff[0] = 0xb0;
    ucCM_InsBuff[1] = 0x00;
    ucCM_InsBuff[2] = ucCryptoAddr;
    ucCM_InsBuff[3] = ucCount;

    // Two bytes of the command must be included in the polynominals
    cm_GPAcmd2(ucCM_InsBuff);
    
    // Include the data in the polynominals and encrypt it required
    cm_GPAencrypt(ucCM_Encrypt, pucBuffer, ucCount); 

	// Write the data
	ucReturn = cm_WriteCommand(ucCM_InsBuff, pucBuffer,ucCount);

	// when anti-tearing, the host should send ACK should >= 20ms after write command
	if (ucCM_AntiTearing) CM_LOW_LEVEL.WaitClock(100);	//10

	return ucReturn;
}