From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vx0-f171.google.com (mail-vx0-f171.google.com [209.85.220.171]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 3E53F20069D for ; Wed, 14 Mar 2012 13:09:01 -0700 (PDT) Received: by vcbfl15 with SMTP id fl15so4706330vcb.16 for ; Wed, 14 Mar 2012 13:09:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=18xEF/ApqBhq6uUHv+zb+rnrUSGTcFRtm2P1Ul4loQY=; b=d8C0Cxvioh/+ysbvCS1HNBG74tX/hzHoHHP1QbLYLi1EubIpljiXC88cC1CXlducuV /6SparhFJbpG/b0xora26fgPHDi9hP/Z7EL/vp3/xmlnS0J00T/xMf/mWywloKaHLtQ4 J1QEneugvR7QqSzWlvQY4IGrgA3Ttj1YCnXYscmKK0C/SRAx3KeiOGd5rOdvZ4H6DGRF 93jwXNy0kScvRYsIRTznZf2F50th0CHSL0VAcdEIpC2glaO0idD8TvpRSQJ1m5AcnG65 W4ZJ8pnrkmnxBUK/jRoo5rflMJfJ2GFI/UdiRzS4ttLAc6EjFw1ETZvJPdlNq9sNukej 8t+w== MIME-Version: 1.0 Received: by 10.52.21.51 with SMTP id s19mr2906896vde.35.1331755740312; Wed, 14 Mar 2012 13:09:00 -0700 (PDT) Received: by 10.220.140.132 with HTTP; Wed, 14 Mar 2012 13:09:00 -0700 (PDT) In-Reply-To: References: <20120314104920.697EA40617@snark.thyrsus.com> <20120314184258.GA30210@thyrsus.com> Date: Wed, 14 Mar 2012 15:09:00 -0500 Message-ID: From: Patrick Maupin To: Dave Taht Content-Type: text/plain; charset=ISO-8859-1 Cc: thumbgps-devel@lists.bufferbloat.net, Andrew McGregor Subject: Re: [Thumbgps-devel] USB handshake signals and Linux X-BeenThere: thumbgps-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Mar 2012 20:09:01 -0000 On Wed, Mar 14, 2012 at 1:57 PM, Dave Taht wrote: > In a private chat late last night andrew mentioned that the ftdi devices > were extensively reprogrammable, in that they came as a usb device > but were really, underneath, just a bunch of gpios... Yes and no. The bandwidth associated with using them as GPIOs is relatively high compared to using them for serial ports. They have a lot of logic to support serial communication and also (in some cases -- not all devices have this) some other modes like SPI, I2C, JTAG, or CPU bus emulation. I have personally used them in serial, parallel FIFO (a fast serial emulation), GPIO, and JTAG modes.