PortIn(Port0,0x7878000)

 (p18,p17,p16,p15,p11,p12,p14,p13)

pc.printf(..., s,s&0x80,s&0x40,s&0x20,s&0x10,s&0x8,s&0x4,s&0x2,s&0x1)

 (8,4,2,1,256,512,1024,2048)

 int top = s >> 19;         // Isolate the top nibble
        int middle = s >> 2;       // Isolate bits 2 & 3
        s = s & 0x00000003;   // Isolate bits 0 & 1      
        s += middle;
        s += top;

Weird! Using <<code>> PortIn(Port0,0x7878000) <</code>> , which is <<code>> (p18,p17,p16,p15,p11,p12,p14,p13) <</code>> , I read the portIn value. I am extremely confused about the bit order of the received byte. Using this code to print every bit: <<code>> pc.printf(..., s,s&0x80,s&0x40,s&0x20,s&0x10,s&0x8,s&0x4,s&0x2,s&0x1) <</code>> , I see that, when pin input is HIGH, the value of the bits is: <<code>> (8,4,2,1,256,512,1024,2048) <</code>> What is the correct order to read one byte from PortIn? PS I' ve found a function to read a byte from PortIn, but seems not to work and is even more confusing: <<code>> int top = s >> 19; // Isolate the top nibble int middle = s >> 2; // Isolate bits 2 & 3 s = s & 0x00000003; // Isolate bits 0 & 1 s += middle; s += top; <</code>> So what the hell is going on here? THANKS everybody!!