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http://www.atmel.com/dyn/resources/prod_documents/doc3ab877f2ec329.pdf


I would like to work to 9600 bauds, I change the TH1 register value to 0FDH and the SR_SPEED to 4, but this application don´t works with this values.
Somebody can help me?
Thanks.

Now works fine, we should not change the value of the TH1 register, always 0E8H.

But, what are the values for SR_SPEED variable, if we have TH1=0FDH ?



]]> Thu, 02 Oct 2008 05:01:07 -0700 http://www.8051projects.net/forum-t13430.html Re: Second asynchronous interface on a 80C51- atmel application note http://www.8051projects.net/forum-t13430.html
But what i felt from application note i explained. code is bit confusing, but still ok if it works.

If you want you can try code in tutorial too.]]> contact@nospam.com (Ajay Bhargav) Fri, 03 Oct 2008 12:39:12 -0700 http://www.8051projects.net/forum-t13430.html Re: Second asynchronous interface on a 80C51- atmel application note http://www.8051projects.net/forum-t13430.html
so you should not play with the timer instead you just have to vary si_count variable's value to change your final baud rate.

if you looked in our tutorial section, you will find software uart code in Serial Communication tutorial, which can be used with assembly as well as C programs. I am sure it will be useful for you. Drawback is you can only have half duplex communication.]]> contact@nospam.com (Ajay Bhargav) Thu, 02 Oct 2008 14:55:44 -0700 http://www.8051projects.net/forum-t13430.html Re: Second asynchronous interface on a 80C51- atmel application note http://www.8051projects.net/forum-t13430.html contact@nospam.com (Ajay Bhargav) Thu, 02 Oct 2008 14:56:18 -0700 http://www.8051projects.net/forum-t13430.html Re: Second asynchronous interface on a 80C51- atmel application note http://www.8051projects.net/forum-t13430.html Many thanks
]]> contact@nospam.com (Ajay Bhargav) Fri, 03 Oct 2008 00:18:13 -0700 http://www.8051projects.net/forum-t13430.html Re: Second asynchronous interface on a 80C51- atmel application note http://www.8051projects.net/forum-t13430.html Nicolas30 wrote ...

Thank you Ajay, but I need to have two 9600 bauds serial port, for this reason I need to load the register TH1 with 0FDH value, in this situation I dont know which is the si_count variable to make the second serial port works properly to 9600 bauds.
Many thanks


@Nicolas30

As I understand the method,
for hardware and software ports to be the same set si_count to 32
as they do in the pdf.

Just don't ask me why

]]> contact@nospam.com (Ajay Bhargav) Fri, 03 Oct 2008 16:54:49 -0700 http://www.8051projects.net/forum-t13430.html Re: Second asynchronous interface on a 80C51- atmel application note http://www.8051projects.net/forum-t13430.html after all its software.. ]]> contact@nospam.com (Ajay Bhargav) Tue, 07 Oct 2008 06:19:59 -0700 http://www.8051projects.net/forum-t13430.html Re: Second asynchronous interface on a 80C51- atmel application note http://www.8051projects.net/forum-t13430.html in the transmission there is no problem
but the problem is in the reception to synchronize the data input, we can do that by pooling or through an external interrupt.
Thx
]]> contact@nospam.com (Ajay Bhargav) Mon, 06 Oct 2008 03:52:31 -0700 http://www.8051projects.net/forum-t13430.html Re: Second asynchronous interface on a 80C51- atmel application note http://www.8051projects.net/forum-t13430.html
rxd ----------- int0
|____P0.5

thnx.
]]> contact@nospam.com (Ajay Bhargav) Fri, 10 Oct 2008 03:25:42 -0700 http://www.8051projects.net/forum-t13430.html Re: Second asynchronous interface on a 80C51- atmel application note http://www.8051projects.net/forum-t13430.html I think its the best method to use soft UART.

If possible provide your proposed schematic, I will add it in my tutorial will be helpful to everyone.]]> contact@nospam.com (Ajay Bhargav) Tue, 14 Oct 2008 07:09:16 -0700 http://www.8051projects.net/forum-t13430.html