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From: Wolfgang Denk <wd@denx.de>
To: Ricardo Ribalda Delgado <ricardo.ribalda@uam.es>
Cc: jan.nikitenko@gmail.com,
	Lorenz Kolb <lorenz@missinglinkelectronics.com>,
	dbrownell@users.sourceforge.net, Joachim Foerster <JOFT@gmx.de>,
	hp@axis.com, linuxppc-dev@ozlabs.org, mike@steroidmicros.com,
	pierre@ossman.eu, joachim@missinglinkelectronics.com,
	john.linn@xilinx.com, linuxkernel@vger.kernel.org
Subject: Re: SD card over (xilinx_)SPI, timeout error while CID
Date: Thu, 11 Jun 2009 23:07:51 +0200	[thread overview]
Message-ID: <20090611210751.A7130832E416@gemini.denx.de> (raw)
In-Reply-To: <aa76a2be0906111349s2ff947eo35149ef14e29d05a@mail.gmail.com>

Dear Ricardo Ribalda Delgado,

In message <aa76a2be0906111349s2ff947eo35149ef14e29d05a@mail.gmail.com> you wrote:
> 
> > What frequency does Your SPI-Bus use?
> 
> 33Mhz.... arghh. just checked is over the standard...  Tomorrow I will
> test with a slower clk

Just some really stupid questions:

This is with a 4xx core, right? Is this the same SPI controller design
like in AMCC's 40x and 44x cores, i. e. with a "FIFO" of depth 1?

Assuming you're running your SPI clock at 1 MHz,  you  get  one  data
byte  and  thus  one interrupt at a rate of 125 kHz. I doubt your CPU
can handle such a load?


Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
A witty saying proves nothing, but saying  something  pointless  gets
people's attention.

  reply	other threads:[~2009-06-11 21:07 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-05 15:34 SD card over (xilinx_)SPI, timeout error while CID Joachim Foerster
2009-06-05 21:15 ` John Linn
2009-06-06 15:14 ` Peter Korsgaard
2009-06-08 15:14   ` Lorenz Kolb
2009-06-09 17:26 ` Joachim Foerster
2009-06-11 19:15   ` Ricardo Ribalda Delgado
     [not found]   ` <aa76a2be0906111215j15933053rf128f1985a982ca0__26561.0047536486$1244748319$gmane$org@mail.gmail.com>
2009-06-11 20:05     ` Lorenz Kolb
2009-06-11 20:49       ` Ricardo Ribalda Delgado
2009-06-11 21:07         ` Wolfgang Denk [this message]
2009-06-11 21:16           ` Ricardo Ribalda Delgado

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