Hi to all engineers.

I need to learn more about uart, i2c serial communications is there any
web site available?
few questions I have.

1. since asynchronies method first sends start bit, data , parity then
stop bit what if my data is four bit
long how does it work since stop bit is 10th bit how does receiver
figure out that data is less then 8 bit.

2. since start bit always is logic 1 stop bit is logic 0  is there any
rule for this  to be always 1 for
start bit 0 for stop bit . what if some one modifies it just to be
opposite.

3. is there any UART sample code that I can play with it?



thank you



Andre