2009-08-07 03:52:24     Problem using UART1 (ttyBF1) on ADZS-BF537-STAMP

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2009-08-07 03:52:24     Problem using UART1 (ttyBF1) on ADZS-BF537-STAMP

Roland Laurès (FRANCE)

Message: 78480   

 

Hi,

 

I'm trying to setup a modem connection throught the ttyBF1 connection. I saw it is possible with pppd and chat as on a standart linux box. The problem is that for an unknown reason on the ADZS-BF537-STAMP board, the UART1 seems corrupt by some other blackfin uc fonctionnalities : I have a level of 1.1 V on the Tx and a pulled low (by around 160 ohm) Rx. This prevent totally the uart from working... I think I perhaps forgot to remove an incompatible functionnality in the kernel. But I can't figure out.

 

If some one can help, Thanks.

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2009-08-07 04:08:19     Re: Problem using UART1 (ttyBF1) on ADZS-BF537-STAMP

Sonic Zhang (CHINA)

Message: 78481   

 

Does the default bf537-stamp configuration with UART1 enabled works on your board?

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2009-08-07 05:07:19     Re: Problem using UART1 (ttyBF1) on ADZS-BF537-STAMP

Roland Laurès (FRANCE)

Message: 78492   

 

Thanks for your quick answer, yes this is doing the same thing. I tested by juste changing the UART1 setting in the kernel.

 

We had the same problem on a board which was from our distributor. We though the board was broken. Then we decided to bought a new one. And this new one is a ADZS-BF537-STAMP V2.1 with a BF537 rev 0.3 on it.

 

There is perhaps a hardware setting i must change to allow using this uart. But I didn't find any clue about it on the schematics...

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2009-08-07 06:13:10     Re: Problem using UART1 (ttyBF1) on ADZS-BF537-STAMP

Sonic Zhang (CHINA)

Message: 78495   

 

What's your kernel release version? We have test uart1 on bf537-stamp v2.1 with chip 0.2 against all blackfin Linux release. No problem are found. What uart1 daughter board do you connect to bf537-stamp? Design by yourself?

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2009-08-07 07:33:15     Re: Problem using UART1 (ttyBF1) on ADZS-BF537-STAMP

Roland Laurès (FRANCE)

Message: 78502   

 

I use the kernel delivered in the 2008RC1.5-RC3 of your uClinux distribution.

 

I'm currently connecting nothing on that UART, I just look with a probe the levels...

 

The first board we used was a 0.2 revision of the BF537, then I doubt the problem comes with the revision of the blackfin processor.

 

I saw that the pins uses for the UART are also use for timers functions. Is it possible that there is a conflict there ? generally several function cannot be selected at the same time... But I ask just in case.

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2009-08-07 07:46:43     Re: Problem using UART1 (ttyBF1) on ADZS-BF537-STAMP

Roland Laurès (FRANCE)

Message: 78503   

 

OK, I solved it... I thought it will be stupid and it was...

 

Those pins are also used for the buttons. And I guess that on the two boards i had, there was by default connected to those buttons...

 

Ok the issue is closed...

 

Thanks for help.

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