Hi
I have used TI spra633 code for McBSP as UART and it didnt work at all. It gives
nothing on hyperterminal. Moreover, the screen of CCS shows Processing transmit
string and nothing else? Can anyone help.
One more problem is when I used simple McBsp and get data from DX pin and
transmit it to PC through MAX232, I get nothing on hyperterminal. However I have
set the CLKGDV so that the CLKX rate can be similar to PC baud rate. Can anyone
tell where the problem is?
_____________________________________
Mcbsp as UART
Started by ●September 10, 2009
Reply by ●September 11, 20092009-09-11
ayesha,
There are several discussions [including code] in the archives by folks who
have successfully used the app note.
mikedunn
On Thu, Sep 10, 2009 at 12:18 AM, wrote:
>
> Hi
>
> I have used TI spra633 code for McBSP as UART and it didnt work at all. It
> gives nothing on hyperterminal. Moreover, the screen of CCS shows Processing
> transmit string and nothing else? Can anyone help.
>
> One more problem is when I used simple McBsp and get data from DX pin and
> transmit it to PC through MAX232, I get nothing on hyperterminal. However I
> have set the CLKGDV so that the CLKX rate can be similar to PC baud rate.
> Can anyone tell where the problem is?
>
>
--
www.dsprelated.com/blogs-1/nf/Mike_Dunn.php
There are several discussions [including code] in the archives by folks who
have successfully used the app note.
mikedunn
On Thu, Sep 10, 2009 at 12:18 AM, wrote:
>
> Hi
>
> I have used TI spra633 code for McBSP as UART and it didnt work at all. It
> gives nothing on hyperterminal. Moreover, the screen of CCS shows Processing
> transmit string and nothing else? Can anyone help.
>
> One more problem is when I used simple McBsp and get data from DX pin and
> transmit it to PC through MAX232, I get nothing on hyperterminal. However I
> have set the CLKGDV so that the CLKX rate can be similar to PC baud rate.
> Can anyone tell where the problem is?
>
>
--
www.dsprelated.com/blogs-1/nf/Mike_Dunn.php
Reply by ●October 8, 20092009-10-08
Ayesha-
> I have used TI spra633 code for McBSP as UART and it didnt work
> at all. It gives nothing on hyperterminal. Moreover,
> the screen of CCS shows Processing transmit string and nothing
> else? Can anyone help.
Did you make progress on this? If you're still having trouble, can you post more specific questions? Just saying "it
doesn't work" makes it harder (and less fun) for other group members to help.
> One more problem is when I used simple McBsp and get data from
> DX pin and transmit it to PC through MAX232, I get
> nothing on hyperterminal. However I have set the CLKGDV so that
> the CLKX rate can be similar to PC baud rate. Can
> anyone tell where the problem is?
How are you sure the DX pin is not active? Did you look at the pin on the scope? That's a good starting point --
don't worry about the external terminal at all, just program the McBSP as needed, don't use DSP interrupts, and create
a software loop that continuously transmits a character, waits for the TXRDY status bit to be valid, then transmits
again. First, program the software loop to repeat the same char, such as 0x55 (ASCII 'U'), and look at the DX pin on
the scope. If you see a continuous 0/1 pattern separated by start and stop bits (hopefully), then you can measure the
bit period to see if your baud rate is approximately correct. Second, change the software loop to output 'A' to 'z'
sequentially then repeat, and capture the DX pin on the scope. Can you see the correct bit order? Are any chars
missing?
-Jeff
_____________________________________
> I have used TI spra633 code for McBSP as UART and it didnt work
> at all. It gives nothing on hyperterminal. Moreover,
> the screen of CCS shows Processing transmit string and nothing
> else? Can anyone help.
Did you make progress on this? If you're still having trouble, can you post more specific questions? Just saying "it
doesn't work" makes it harder (and less fun) for other group members to help.
> One more problem is when I used simple McBsp and get data from
> DX pin and transmit it to PC through MAX232, I get
> nothing on hyperterminal. However I have set the CLKGDV so that
> the CLKX rate can be similar to PC baud rate. Can
> anyone tell where the problem is?
How are you sure the DX pin is not active? Did you look at the pin on the scope? That's a good starting point --
don't worry about the external terminal at all, just program the McBSP as needed, don't use DSP interrupts, and create
a software loop that continuously transmits a character, waits for the TXRDY status bit to be valid, then transmits
again. First, program the software loop to repeat the same char, such as 0x55 (ASCII 'U'), and look at the DX pin on
the scope. If you see a continuous 0/1 pattern separated by start and stop bits (hopefully), then you can measure the
bit period to see if your baud rate is approximately correct. Second, change the software loop to output 'A' to 'z'
sequentially then repeat, and capture the DX pin on the scope. Can you see the correct bit order? Are any chars
missing?
-Jeff
_____________________________________
