void TWI_MasterMode_Write(unsigned short DeviceAddr, unsigned char *TWI_Data_Pointer, unsigned short Count, unsigned short TWI_Length)
{
    int i, j, timeout;

    if (*pTWI_MASTER_STAT & SDASEN)
    {
        if(!ClrSclSda())
            return;
    }
    
    /* make sure no previous errors occured */
    if (TWISuccess == 1)
    {            

        *pTWI_FIFO_CTL = 0;                                    /* clear the bit manually */
        *pTWI_CONTROL = TWI_ENA | PRESCALE_VALUE;            /* PRESCALE = fsclk/10MHz */
        *pTWI_CLKDIV = ((CLKDIV_HI) << 8) | (CLKDIV_LO);    /* CLKDIV = (1/SCL)/(1/10MHz) */
        *pTWI_MASTER_ADDR = DeviceAddr;                        /* target address (7-bits plus the read/write bit) */

        for (i = 0; i < Count; i++)
        {
            /* # of configurations to send */
            *pTWI_XMT_DATA8 = *TWI_Data_Pointer++;    /* pointer to data */
            ssync();
    
            *pTWI_MASTER_CTL = (TWI_Length<<6) | MEN /*| FAST*/;    /* start transmission */

            timeout = 0x1000;
        
            for (j = 0; j < (TWI_Length-1); j++)
            {
                /* # of transfers before stop condition */
                while ((*pTWI_FIFO_STAT == XMTSTAT) && --timeout)    /* wait to load the next sample into the TX FIFO */     // TAR37913
                {
                    ssync();
                }
                if(!timeout)
                    return;

                *pTWI_XMT_DATA8 = *TWI_Data_Pointer++;        /* load the next sample into the TX FIFO */
                ssync();
            }
            
            timeout = 0x1000;
            
            while (!(*pTWI_INT_STAT & MCOMP) && --timeout)            /* wait until transmission complete and MCOMP is set */
            {
                ssync();
            }
            if(!timeout)
                return;
    
            /* check if an error occured */
            if ((*pTWI_INT_STAT & MERR) == MERR)
            {
                *pTWI_INT_STAT |= MERR;
                TWISuccess = 0;        
            }
        
            *pTWI_INT_STAT = XMTSERV | MCOMP;                /* service TWI for next transmission */
        }
    }

    asm("nop;");
    asm("nop;");
    asm("nop;");
}

这个是TWI写程序，我想问问写入的话先要找到从机地址，再找到寄存器地址，再写入数据，我怎么调用这个函数啊，它就只有一个形参是从机地址，我怎么写入从机内部寄存器地址？？

我这样可以吗？

那么读数据也是这样吗？

void TWI_MasterMode_Read(unsigned short DeviceAddr, unsigned char *TWI_Data_Pointer, unsigned short Count)

可以，但写入的数据可能无效，因为有可能处理器认为IIC只写了1个寄存器的地址，并没有给地址赋值，就结束了。你试试。