kkk

sfr ...
sbit ...

sbit salida = P1^0;

void main (void) {

    // medir 50 ms
    TR0 = 0;
    TF0 = 0;
    TMOD & = 0xF1;
    TMOD | = 0x01;
    TH0 = (65536 -50000) >> 8;
    TL0 = (65536 -50000) & 0xFF;
    salida = 0;
    TRO=1;
    while (TF0 == 0) {};
    salida = 1;
}