Data Transmission: Constructing Digital Circuits & Clock Pulses

[ws0619]

Hi!
I would like to construct a digital circuit as like how computer transmit data.

My problem is how can I make start bit and stop bit for my 7 bits data?and how can the receiver knows that that is start bit and not the data?(I confuse at this part)

While sending data, how can I scrambling the data?And actually does this scrambling process important in sending data?

To make the sending data clear, I want to increase the clock pulse between the data during sending.How can I do it?

Thanks!

 

[Bob S]

I have used the Manchester (NRZ) code in the past. This Wiki mentions the code, but some
http://en.wikipedia.org/wiki/Self-clocking_signal
more elaboration is required. Before the data is sent, a sufficient number of clock cycles must be sent to permit the receiver time to synchronize its clock to the sending clock. Usually, the clock pulse stream is continuous. Second, you need a parity bit at the end, not only as a parity check, but also to make sure that the total number of transitions in the data stream is always even (or odd).
Bob S

 

[berkeman]

I have used the Manchester (NRZ) code in the past. This Wiki mentions the code, but some
http://en.wikipedia.org/wiki/Self-clocking_signal
more elaboration is required. Before the data is sent, a sufficient number of clock cycles must be sent to permit the receiver time to synchronize its clock to the sending clock. Usually, the clock pulse stream is continuous. Second, you need a parity bit at the end, not only as a parity check, but also to make sure that the total number of transitions in the data stream is always even (or odd).
Bob S

And here is a wiki article to give you some reading to do...

http://en.wikipedia.org/wiki/Data_transmission

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