char DATA;
char code TblCallKey[12] = {
    
    0xed,0xeb,0xe7,0xdd,0xdb,0xd7,0xbd,0xbb,0xb7,0x7d,0x7b,0x77

};
main()
{
       EA=false;
       SystemInitialize();    // Program system intialization status
       EA = TRUE;
       while(true)
       {
         for(i=0; i<12;i++)
         SBUF=DATA | TblCallKey[i];
        
       }
}
serial () interrupt 4 using 2
{
                            
            // if serial port interrupt
        if (TI==TRUE)
        {
            TI=FALSE;
            STB=TRUE;                
        
            DelayX10ms(1);    
        }
    
}
void SystemInitialize()
{
    SCON  = 0x00;                    
    TMOD |= 0x21;                    
    TH1   = 230;                    
    TL1 = 230;
    TR1   = true;                    
    RI  = false;            
    ES    = true;                    
    TF0 = true;                    
    TR0 = true;                    
    TH0 = TIME_4MS >> 8;                    
    
    TL0 = TIME_4MS & 0x00FF       
    ET0 = true;                    
                
}
这个程序是用C51写的，麻烦那位有这方面的经验，指点一二。