unsigned char coding(unsigned char m )  解释下这个参数m是什么   谢谢哈  要是能帮忙解释下这篇各句实现什么功能最好哈     
{
    unsigned char k;
   
    switch(m)
    {
        case (0x11): k=1;break;
        case (0x21): k=2;break;
        case (0x41): k=3;break;
        case (0x81): k='A';break;
        case (0x12): k=4;break;
        case (0x22): k=5;break;
        case (0x42): k=6;break;
        case (0x82): k='B';break;
        case (0x14): k=7;break;
        case (0x24): k=8;break;
        case (0x44): k=9;break;
        case (0x84): k='C';break;
        case (0x18): k='*';break;
        case (0x28): k=0;break;
        case (0x48): k='#';break;
        case (0x88): k='D';break;
    }
    return(k);
}

大家来帮帮忙哈