Serial & Parallel Communications,limitations of parallel communication & adventages of serial communication.txt

1.Introduction to Serial Communication:
----------------------------
what is Parallel Communication:
	>Data transfer b/w 2 modules is parallel
	>it is high speed communication & low distance communication(<1feet)
	>ex: In mother board data transfer b/w processor modules & other
what is Serial Communication : 
	>Data transfer b/w 2 modules is series 
     >it is low speed communication & long distance communication(>1feet)
     >ex: Communication b/w compputer & other Pheriperal devices

limitations of parallel Communication:
	>for longer distance(>1feet) parallel communication may leads to 
errors in bits recevied in reciever modules due to wire thickness.

how to avoid this error? 
	Transmitter                              Reciever
     -----------                              --------
parallel           Serial                      Serial            parallel
Communications >to>Communication   >tranfer>   Communication >to>Communication

Serial communication : 
    2types : 
    >1.Synchronus serial communication
       depends on clk               
                 Tx > transer data in (negedge clk)
			 Rx > recieve data in (posedge clk)             
    >2.Asynchronus serial communication
       doesnot depends on clk
                  __________ ______ ____________
           Tx  > |stopbit(1)| Data | startbit(0)| > Rx
                 |__________|______|____________|