From: Alexander Stein <alexander.stein@systec-electronic.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Grant Edwards <grant.b.edwards@gmail.com>,
linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org
Subject: Re: [PATCH] Documentation about RS485 serial communications
Date: Tue, 19 Oct 2010 17:27:27 +0200 [thread overview]
Message-ID: <201010191727.53314.alexander.stein@systec-electronic.com> (raw)
In-Reply-To: <i9ka0s$4ua$1@dough.gmane.org>
On Tuesday 19 October 2010, 16:29:48 Grant Edwards wrote:
> On 2010-10-19, Claudio Scordino <claudio@evidence.eu.com> wrote:
> > +2. HARDWARE-RELATED CONSIDERATIONS
> > +
> > + Some CPUs (e.g., Atmel AT91) contain a transceiver capable of working
> > both + as RS232 and RS485.
>
> Pardon my curiosity, but I've looked at a few AT91 parts, and I've
> never seen on with an internal transceiver -- nor does Google seem
> able to find any.
>
> Frankly, I'd be pretty surprised, since it would be very difficult
> (fab-wise), to build a mircoprocessor with I/O cells capable of
> withstanding the voltage levels specified in RS232.
>
> Can you specify to which parts you're referring?
I doubt the AT91 do have an internal transceiver but it has a dedicated pin
feature (RTS or CTS or something) which can be used to switch between RS232
and RS485 by setting a bit in the USART provided the pin is connected
properly.
Regards,
Alexander
next prev parent reply other threads:[~2010-10-19 15:27 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20100408111310.524f7354@lxorguk.ukuu.org.uk>
[not found] ` <4BBDD71D.1010700@evidence.eu.com>
[not found] ` <4BFD1FB6.8050405@atmel.com>
[not found] ` <4BFE2F38.8050200@evidence.eu.com>
[not found] ` <4BFE41FD.2080804@atmel.com>
[not found] ` <20100527102917.GB31253@pengutronix.de>
[not found] ` <4C626CBF.9020609@evidence.eu.com>
[not found] ` <20100811083214.21d2919e.randy.dunlap@oracle.com>
[not found] ` <4C669120.8080707@evidence.eu.com>
[not found] ` <4C686411.3060500@oracle.com>
[not found] ` <20100815221906.GA24153@n2100.arm.linux.org.uk>
2010-10-19 12:28 ` [PATCH] Documentation about RS485 serial communications Claudio Scordino
2010-10-19 14:29 ` Grant Edwards
2010-10-19 15:27 ` Alexander Stein [this message]
2010-10-19 17:22 ` Grant Edwards
2010-10-20 8:00 ` Alexander Stein
2010-10-20 18:56 ` Alan Cox
2010-10-24 11:29 ` Claudio Scordino
2010-11-10 9:17 ` Nicolas Ferre
2010-11-10 17:28 ` Greg KH
2010-11-11 10:22 ` Claudio Scordino
2010-11-16 14:30 ` Pavel Machek
2010-11-16 14:58 ` Tosoni
2010-11-16 15:52 ` Grant Edwards
2010-11-16 15:23 ` Grant Edwards
2010-11-16 15:28 ` Alexander Stein
2010-11-16 16:13 ` Matt Schulte
2010-11-16 16:28 ` Grant Edwards
2010-11-16 18:41 ` Matt Schulte
2010-11-16 19:29 ` Grant Edwards
2010-11-16 17:20 ` Alan Cox
2010-11-16 18:03 ` Grant Edwards
2010-11-16 20:04 ` Alan Cox
2010-11-30 19:19 ` Pavel Machek
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