All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Stuart MacDonald" <stuartm@connecttech.com>
To: "'linux-os \(Dick Johnson\)'" <linux-os@analogic.com>,
	"'Krzysztof Halasa'" <khc@pm.waw.pl>
Cc: "'Alan Cox'" <alan@lxorguk.ukuu.org.uk>,
	"'David Woodhouse'" <dwmw2@infradead.org>,
	<linux-serial@vger.kernel.org>,
	"'LKML'" <linux-kernel@vger.kernel.org>
Subject: RE: Serial custom speed deprecated?
Date: Fri, 25 Aug 2006 11:17:42 -0400	[thread overview]
Message-ID: <043401c6c859$9c611350$294b82ce@stuartm> (raw)
In-Reply-To: <Pine.LNX.4.61.0608241635090.13499@chaos.analogic.com>

From: On Behalf Of linux-os (Dick Johnson)
> But the baud-rates have always been some approximation that starts
> at 75 and increases by powers-of-two. This is because the hardware
> always had fixed clocks with dividers that divided by powers-of-two.
> What is the claim for the requirement of strange baud-rates set
> as an integer of dimension "baud?" Where does this requirement
> come from and what devices use these?

Perhaps you'd like to check out our products
http://www.connecttech.com/

We build a lot of custom boards that have odd clocks to generate very
odd baud rates for random serial devices. The Bxxx style has been a
thorn in my side since 1999.

Also, Oxford's 16PCI95x family has three different points of altering
the clock; the clock prescaler, the actual sample rate (which is the
classic /16 that most are used to), and the actual divisor. That can
produce pretty much any baud rate, albeit with some error.

..Stu


WARNING: multiple messages have this Message-ID (diff)
From: "Stuart MacDonald" <stuartm@connecttech.com>
To: "'linux-os (Dick Johnson)'" <linux-os@analogic.com>,
	'Krzysztof Halasa' <khc@pm.waw.pl>
Cc: 'Alan Cox' <alan@lxorguk.ukuu.org.uk>,
	'David Woodhouse' <dwmw2@infradead.org>,
	linux-serial@vger.kernel.org,
	'LKML' <linux-kernel@vger.kernel.org>
Subject: RE: Serial custom speed deprecated?
Date: Fri, 25 Aug 2006 11:17:42 -0400	[thread overview]
Message-ID: <043401c6c859$9c611350$294b82ce@stuartm> (raw)
In-Reply-To: <Pine.LNX.4.61.0608241635090.13499@chaos.analogic.com>

From: On Behalf Of linux-os (Dick Johnson)
> But the baud-rates have always been some approximation that starts
> at 75 and increases by powers-of-two. This is because the hardware
> always had fixed clocks with dividers that divided by powers-of-two.
> What is the claim for the requirement of strange baud-rates set
> as an integer of dimension "baud?" Where does this requirement
> come from and what devices use these?

Perhaps you'd like to check out our products
http://www.connecttech.com/

We build a lot of custom boards that have odd clocks to generate very
odd baud rates for random serial devices. The Bxxx style has been a
thorn in my side since 1999.

Also, Oxford's 16PCI95x family has three different points of altering
the clock; the clock prescaler, the actual sample rate (which is the
classic /16 that most are used to), and the actual divisor. That can
produce pretty much any baud rate, albeit with some error.

..Stu


  parent reply	other threads:[~2006-08-25 15:18 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-08-23 21:41 Serial custom speed deprecated? Stuart MacDonald
2006-08-24  9:18 ` David Woodhouse
2006-08-24 12:41   ` Stuart MacDonald
2006-08-24 13:19     ` Alan Cox
2006-08-24 13:03       ` David Woodhouse
2006-08-24 16:27   ` Krzysztof Halasa
2006-08-24 17:41     ` Alan Cox
2006-08-24 18:51       ` Krzysztof Halasa
2006-08-24 20:43         ` linux-os (Dick Johnson)
2006-08-24 20:43           ` linux-os (Dick Johnson)
2006-08-24 22:11           ` Alan Cox
2006-08-27  6:52             ` Rogier Wolff
2006-08-27  6:52               ` Rogier Wolff
2006-08-27 10:00               ` Russell King
2006-08-28 14:14               ` Stuart MacDonald
2006-08-28 14:14                 ` Stuart MacDonald
2006-08-28 20:09                 ` Russell King
2006-08-29  6:20                   ` Rogier Wolff
2006-08-29  6:20                     ` Rogier Wolff
2006-08-29  7:46                     ` Russell King
2006-08-25 15:17           ` Stuart MacDonald [this message]
2006-08-25 15:17             ` Stuart MacDonald
2006-08-25 15:52             ` linux-os (Dick Johnson)
2006-08-25 15:52               ` linux-os (Dick Johnson)
2006-08-24 22:43         ` Alan Cox
2006-08-25 10:58           ` Krzysztof Halasa
2006-08-25 15:21           ` Stuart MacDonald
2006-08-25 15:21             ` Stuart MacDonald
2006-08-25 19:32             ` Russell King
2006-08-25 20:21               ` Stuart MacDonald
2006-08-25 20:21                 ` Stuart MacDonald
2006-08-25 20:54                 ` linux-os (Dick Johnson)
2006-08-25 20:54                   ` linux-os (Dick Johnson)
2006-08-25 20:39               ` Theodore Tso
2006-08-26 12:16                 ` Krzysztof Halasa
2006-08-25 15:10         ` Stuart MacDonald
2006-08-25 15:10           ` Stuart MacDonald
2006-08-24 22:05       ` Russell King
2006-08-25 15:01       ` Stuart MacDonald
2006-08-25 15:01         ` Stuart MacDonald
     [not found] <6N8LR-22A-5@gated-at.bofh.it>
     [not found] ` <6Njxz-797-13@gated-at.bofh.it>
     [not found]   ` <6NqfR-5Ld-49@gated-at.bofh.it>
     [not found]     ` <6NrbQ-7Ab-27@gated-at.bofh.it>
     [not found]       ` <6NsB4-2GL-37@gated-at.bofh.it>
     [not found]         ` <6NvSc-1go-31@gated-at.bofh.it>
2006-08-25 11:40           ` Nick Craig-Wood
2006-08-26 18:16 linux
2006-08-26 19:37 ` Ian Stirling
2006-08-26 20:30   ` linux
2006-08-28 12:17 ` linux-os (Dick Johnson)
2006-08-28 14:39   ` Alan Cox
2006-08-28 14:50     ` linux-os (Dick Johnson)
2006-08-28 15:51       ` Michael Poole
2006-08-28 16:57         ` linux-os (Dick Johnson)
2006-08-28 17:40           ` Michael Poole
2006-08-28 18:04             ` linux-os (Dick Johnson)
2006-08-28 17:01       ` Alan Cox
2006-08-28 17:24         ` linux
2006-08-26 19:35 linux

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='043401c6c859$9c611350$294b82ce@stuartm' \
    --to=stuartm@connecttech.com \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=dwmw2@infradead.org \
    --cc=khc@pm.waw.pl \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-os@analogic.com \
    --cc=linux-serial@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.