How to calculate the baud rate for UART protocol?

[Mkanimozhi]

Hi,
How to calculate the baud rate for uart protocol, can i get detail description of this soon.and can i get any document to write my own coding in vhdl for UART protocol.

Regards
Kanimozhi.M

 

[sivamit]

Re: baud rate generation

How to calculate the baud rate..?????

Let's assume that you are sending your data to PC at 25Khz after deriving a random freq from the master clock, but actually your PC cannot recieve the data.. because there obviously,will be a baudrate mismatch.There are some predefined baudrate values.. Max is 115.5 Kbps. This you can get from hyper terminal.
If you deviate very much from these values, PC cannot -sample the values and get synchronised. So the answer to your question is, decide upon the baudrate values you are going to use and calculate the freq accordingly.


-Shiva

 

[manish12]

Re: baud rate generation

use counter [ freq divider ] for the same

 

[Mkanimozhi]

baud rate generation

Hi,
I need any good document for code my own VHDL coding for UART, that document should contain all the detail about transmitter,receiver and baud rate generation , can any one provide ,plz

Regards
Kanimozhi.M

 

[sivamit]

Re: baud rate generation

Hi,
I need any good document for code my own VHDL coding for UART, that document should contain all the detail about transmitter,receiver and baud rate generation , can any one provide ,plz

Regards
Kanimozhi.M

Try this...
https://www.asic-world.com/examples/vhdl/uart.html

https://opencores.org/

Ciao,
Shiva

 

[Mkanimozhi]

baud rate generation

Hi,
Thank you, but i need the any document for to understand myself clearly what the internal operations and i need to design myself.

Regards
Kanimozhi.M

 

[sivamit]

Re: baud rate generation

Hi,
Thank you, but i need the any document for to understand myself clearly what the internal operations and i need to design myself.

Regards
Kanimozhi.M

Hi Kani,
I guess itz very easy to design transmitter section first,to start with..
Just write some clock divider program to get a feq about 9500-9700..
And transmit a single character, for e.g. 'S'.
But for this I should know something about RS232 protocol..
Just refer this..

https://www.wcscnet.com/Tutorials/SerialComm/Page1.htm

Otherthan this, u dont need any document...
Just try..U can...


All the best..

-Shiva

 

[satishkumar]

baud rate generation

How to calculate the baud rate for uart protocol?plz any one can explain in numerical?

Thanks in advance

 

[sivamit]

Re: baud rate generation

How to calculate the baud rate for uart protocol?plz any one can explain in numerical?

Thanks in advance

Simple..!!!

[1/T(startbit-stop bit)]*10- if you have only 8 bits of data(i.e. no parity bits)



Ciao,
Shiva

 

[Mkanimozhi]

baud rate generation

Hi ,
it's very simple
system clk frequency/ur baud rate value
and the answer which we are getting here divided by 2


eg,
system clk=20mhz
baud value=9600
so
20mhz/9600=2083.33

now 2083.33/2=1041.66

so ur ciunt value is 1041 and
write the clk divider code for this count u will get the clk to synchronize the two systems.

Regards
Kanimozhi.M

 

[karikalan_t79]

Re: baud rate generation

hi

extacly correct but trans its ok, recevi , you have to div it by 2