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Re: I am so BAUD of this! (PXA26x HWUART)
- From: Gary Thomas <gary at mlbassoc dot com>
- To: davido at hydrix dot com
- Cc: eCos Discussion <ecos-discuss at ecos dot sourceware dot org>
- Date: Thu, 11 Nov 2004 15:48:23 -0700
- Subject: Re: [ECOS] I am so BAUD of this! (PXA26x HWUART)
- Organization: MLB Associates
- References: <1100213175.4243.45.camel@abe.private.hydrix.com>
On Thu, 2004-11-11 at 15:46, David Osborne wrote:
> Hi Gentle Folk,
>
> Our HWUART on the PXA26x processor is being configured by eCos at
> startup to be 115200 bps.
>
> After about 60 seconds our software needs to select a different baud
> rate (usually 9600 bps). We effectively use the same function as eCos
> serial_config_port(...) via the API to change the baud rate. The problem
> is that 50% of the time the baud rate doesn't change, but remains at
> 115200 bps. The DLL & DLH registers reflect our new baud rate settings,
> but physically it still transmits at the original baud rate.
>
> I believe our use of the DLL, DLH, and ABR:ABUP registers are correct,
> and like I said, it works half the time. Could it be the HWUART can only
> be configured immediately after power up? Can the HWUART be reset (not
> just the enable/disable register) by software? So many questions, so
> few answers.
>
> If anyone could help end this misery, and release me from this
> bottomless hole, it would be very much appreciated.
More likely, the UART will not change baud rates unless it is totally
idle. Try making sure that absolutely everything has been clocked out
before trying to change it.
--
Gary Thomas <gary@mlbassoc.com>
MLB Associates
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