Date: Thu, 7 Jun 2007 12:46:37 -0700 (PDT) From: Neil Bradley <nb@synthcom.com> Cc: arm@freebsd.org Subject: Re: 4-bit SD Card mode Message-ID: <20070607123930.E75948@synthcom.com> In-Reply-To: <20070607.133456.74668036.imp@bsdimp.com> References: <50392.2001:6f8:101e:0:20e:cff:fe6d:6adb.1181235257.squirrel@webmail.alpha-tierchen.de> <20070607180946.GK16463@cicely12.cicely.de> <49754.2001:6f8:101e:0:20e:cff:fe6d:6adb.1181244172.squirrel@webmail.alpha-tierchen.de> <20070607.133456.74668036.imp@bsdimp.com>
index | next in thread | previous in thread | raw e-mail
> I'm not sure I like this at all. The devices shouldn't be setting up
> the pins for that device. In some cases, they can't know how to do
> that, and this is one of them. The device has no way of knowing if
> all 4 wires are connected, or just 1 and the 'spare' lines are used
> for GPIO.
Not doing it will irritate more people (i.e. "I'm not getting full speed
out of the SD card). While it's a valid concern, I don't think it's
unrealistic to assume that all 4 DAT lines are hooked up. I've not yet
encountered a design that A) had SD capabilities, B) was only running
single bit because of a lack of GPIOs.
-->Neil
----------------------------------------------------------------------------
C. Neil Bradley - KE7IXP - The one eyed man in the land of the blind is not
king. He's a prisoner.
home |
help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070607123930.E75948>