读卡单片机ID卡读卡器读卡程序

#if EM4150CARDTST 
unsigned char Em4150_CardTst(unsigned char time) 
{ 
    unsigned char n1 = 0; 
     
    emTime1 = time; 
    c(FL_EM, 1); 
     
    n1 = time >> 4;     // time / 16 = 同步头次数 
    while ((FL_EM & 0x02) == 0) 
    { 
        if (b(PINEMDAO, EMDAO) == 0) 
     { 
            TCNT0 = 0; 
         do{ 
                if (FL_EM & 0x02) break; 
            }while (b(PINEMDAO, EMDAO) == 0); 
            if ((TCNT0 > 100) && (TCNT0 < 140)) 
     { 
                TCNT0 = 0; 
         do{ 
                    if (FL_EM & 0x02) break; 
                }while (b(PINEMDAO, EMDAO)); 
                if (TCNT0 > 60) 
         { 
                 TCNT0 = 0; 
         do{ 
                        if (FL_EM & 0x02) break; 
                    }while (b(PINEMDAO, EMDAO) == 0); 
                    if (TCNT0 > 60)