I have a Rabbit RCM 4300 with the protoboard of developer kit RCM 4000. I have wrote a program that use the serial “D” port and the program works very well. Since it is working well, now I want to jump off the RCM 4000 board and develop a external printed circuit utilizing only the RCM 4300. What happened is that when I try to aquire a signal from the PC0 pin, that is the TxD of the RCM 4300, I have no signal. What I`m doing wrong?