From: Geert Uytterhoeven <geert@linux-m68k.org>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] ARM: shmobile: koelsch: Add support HSCIF1
Date: Fri, 13 Jun 2014 14:21:22 +0000 [thread overview]
Message-ID: <CAMuHMdUaO2pANQJCVceEkoJb9QuS7=BO-x3V5eSoBOEeCuOAUg@mail.gmail.com> (raw)
In-Reply-To: <1751840.oCdYe48VRu@avalon>
Hi Laurent,
On Fri, Jun 13, 2014 at 3:24 PM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>> About your comment about the resistors and capacitors, which applies to
>> both HSCIF0 and HSCIF1: probably the serial port will still work if
>> these are present.
>
> With a 4.7µF capacitive load on the transmission line, assuming a drive
> strength of 40mA (which is pretty high), switching between 0V and 3.3V takes
> 388µs, corresponding to 2579 Hz. You'll have to reduce the baud rate :-)
Right, 4.7µF is a bit high. So at least the capacitor has to go for today's
typical serial speeds.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2014-06-13 14:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-10 2:34 [PATCH v2] ARM: shmobile: koelsch: Add support HSCIF1 Nobuhiro Iwamatsu
2014-06-10 4:14 ` Magnus Damm
2014-06-10 7:00 ` Simon Horman
2014-06-13 7:01 ` Laurent Pinchart
2014-06-13 7:43 ` Simon Horman
2014-06-13 10:49 ` Laurent Pinchart
2014-06-13 11:16 ` Geert Uytterhoeven
2014-06-13 13:24 ` Laurent Pinchart
2014-06-13 14:21 ` Geert Uytterhoeven [this message]
2014-06-16 0:09 ` Simon Horman
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