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UART

Luke Vassallo

Dec 10, 2014
33
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Dec 10, 2014
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Hello,

I am currently trying to understand how serial communication works. however i am having a problem understanding how the character frame is interpreted by the hardware. For example how does the UART 'know' which is the start and stop bit, is there some counter implemented that counts the data bits ?

Below is a basic flow diagram of a uart taken from sparkfun.

any tips are welcome
 

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Gryd3

Jun 25, 2014
4,098
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Jun 25, 2014
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4,098
Hello,

I am currently trying to understand how serial communication works. however i am having a problem understanding how the character frame is interpreted by the hardware. For example how does the UART 'know' which is the start and stop bit, is there some counter implemented that counts the data bits ?

Below is a basic flow diagram of a uart taken from sparkfun.

any tips are welcome
Perhaps you should take a look at an example data-stream.
Depending on the implementation, it's either triggered by an extra pin, or a bit with unique timing.
 

Minder

Apr 24, 2015
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Apr 24, 2015
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UART, Asynchronous = Not synchronised by a shared signal such as clock and proceeding independently.
Opposite: synchronous.
A communications system in which data transmission may start at anytime and is indicated by a start bit, e.g. EIA-232. A data byte (or other element defined by the protocol ) ends with a stop bit.
A continuous marking condition is then maintained until data resumes.
The protocol is defined in both TX and RX ends Baud rate, 7/8 bits, stop bit etc.
M.
 
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