From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: EP405 GPIO signal problem From: Toni Van Remortel Reply-To: t.vanremortel@ha.be To: Eugene Surovegin Cc: Embedded PPC In-Reply-To: <20031120181921.GA3365@gate.ebshome.net> References: <1069336934.1290.6.camel@toni> <20031120181921.GA3365@gate.ebshome.net> Content-Type: text/plain Message-Id: <1069402906.4172.6.camel@toni> Mime-Version: 1.0 Date: Fri, 21 Nov 2003 09:21:46 +0100 Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Op do 20-11-2003, om 19:19 schreef Eugene Surovegin: > On Thu, Nov 20, 2003 at 03:02:15PM +0100, Toni Van Remortel wrote: > > I have an RTAI powered kernel module which outputs 32 bits data via the > > EP405 GPIO ports from the IBM 405GP CPU. These outputs are multiplexed > > with other signals. > > Problem: when I output the 32 bits as one like this: > > writel( buffer, (u32)gpio_base_addr+GPIO0_OR ); > > (where buffer is of u32 type) > > One thing which looks strange to me. Are you sure you can use 32 GPIO > pins? Ain't possible, I know. > This is impossible because 405GP has only 23, and I doubt you can use > even this number, because some of the pins are shared with IRQ and > PerCSx lines. You can set all 23 GPIO's as output. I actually only use 17 of them (2 x 8bit position and 1 on/off). Now I've taken a deeper look at the problem, it might be caused by the EP405 itself. My DAC settles at 70ns. I still have to check if the signals are outputted all at the same time. Should go and fetch a logic analyzer somewhere ;) -- Toni Van Remortel Wetenschappelijk Medewerker - D-science lab Real time Linux for embedded systems: http://linemb.d-sciencelab.com Tel: +32 3 205 61 72 - Fax: +32 3 205 61 95 E-mail: t.vanremortel@ha.be ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/