Reply-To: "Cool Morning ..." From: "Cool Morning ..." Newsgroups: comp.arch.fpga Subject: FPGA comes with a DAC? Date: Tue, 10 Sep 2002 08:30:46 +0800 Lines: 16 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 NNTP-Posting-Host: 203.116.53.151 Message-ID: <3d7d3d4d@news.starhub.net.sg> X-Trace: 10 Sep 2002 08:31:09 +0800, 203.116.53.151 Organization: StarHub Internet Pte Ltd Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!newsfeed.icl.net!newsfeed.fjserv.net!opentransit.net!news.tele.dk!small.news.tele.dk!206.252.192.28!news.stealth.net!news.stealth.net!newsvr.starhub.net.sg!news.starhub.net.sg!203.116.53.151 Xref: chonsp.franklin.ch comp.arch.fpga:20807 Hi, I am looking for an FPGA chip which has a built-in DAC. My intend it to build a portable with three chips only, A compact-flash, an FPGA containing the MP3 decoder and Compact flash and USB interface, a power amplifier. Is it possible? What's the SIMPLEST approach possible to make a portable MP3 player in today's technology? Kelvin. ###### Message-ID: <3D7D4BC2.D103915D@mail.com> From: John_H X-Mailer: Mozilla 4.75 [en]C-CCK-MCD (Win95; U) X-Accept-Language: en MIME-Version: 1.0 Newsgroups: comp.arch.fpga Subject: Re: FPGA comes with a DAC? References: <3d7d3d4d@news.starhub.net.sg> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 28 Date: Tue, 10 Sep 2002 01:32:51 GMT NNTP-Posting-Host: 192.65.17.17 X-Complaints-To: postmaster@opbu.xerox.com X-Trace: news-west.eli.net 1031621571 192.65.17.17 (Mon, 09 Sep 2002 19:32:51 MDT) NNTP-Posting-Date: Mon, 09 Sep 2002 19:32:51 MDT Organization: Xerox Officeprinting NewsReader Service Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!newsfeed.icl.net!newsfeed.fjserv.net!newsfeed.news2me.com!arclight.uoregon.edu!logbridge.uoregon.edu!news-west.eli.net!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:20837 Since you recognize the need for a power amplifier, look into Class-D amplifiers. While the one device I glanced at from TI has an analog input and an internal ramp generator, the push-pull FETs give you high efficiency compared to the linear equivalents. If you can find/substitute your own digital to analog equivalent, you can have good THD and great efficiency at some very respectable power levels. There are other D/A techniques that can give you the similar characteristics, but if you're going for minimal, the class-D emulation might get you close to your analog goals. Search this groups.google.com and you might find a few postings about mp3 implementations here and in other newsgroups. "Cool Morning ..." wrote: > Hi, > > I am looking for an FPGA chip which has a built-in DAC. My intend > it to build a portable with three chips only, A compact-flash, an FPGA > containing the MP3 decoder and Compact flash and USB interface, a > power amplifier. Is it possible? > > What's the SIMPLEST approach possible to make a portable MP3 player > in today's technology? > > Kelvin. ###### Path: chonsp.franklin.ch!not-for-mail From: Neil Franklin Newsgroups: comp.arch.fpga Subject: Re: FPGA comes with a DAC? Date: 11 Sep 2002 00:21:39 +0200 Organization: My own Private Self Lines: 25 Message-ID: <6u7kht5vv0.fsf@chonsp.franklin.ch> References: <3d7d3d4d@news.starhub.net.sg> NNTP-Posting-Host: chonsp.franklin.ch X-Trace: chonsp.franklin.ch 1031696499 354 10.0.3.2 (10 Sep 2002 22:21:39 GMT) X-Complaints-To: news@chonsp.franklin.ch NNTP-Posting-Date: 10 Sep 2002 22:21:39 GMT X-Newsreader: Gnus v5.7/Emacs 20.4 Xref: chonsp.franklin.ch comp.arch.fpga:20846 "Cool Morning ..." writes: > I am looking for an FPGA chip which has a built-in DAC. My intend > it to build a portable with three chips only, A compact-flash, an FPGA > containing the MP3 decoder > > What's the SIMPLEST approach possible to make a portable MP3 player > in today's technology? With ->ANY<- FPGA you can implement an Sigma-Delta DAC in the FPGAs normal logic gates. So I doubt you will find an FPGA with hardwired DAC circuits. Specific for Virtex: http://www.xilinx.com/xapp/xapp154.pdf They there show an minimal FPGA+R+C circuit. For audio you will need an second R parallel to the C (acts with first R as voltage divider 3.3->0.12V) and possibly an second C after the R-C connection point (to get rid of DC component, depends on your amplifier chip). -- Neil Franklin, neil@franklin.ch.remove http://neil.franklin.ch/ Hacker, Unix Guru, El Eng HTL/BSc, Programmer, Archer, Roleplayer - Make your code truely free: put it into the public domain ###### Message-ID: <3D7E761B.3351@designtools.co.nz> From: Jim Granville Reply-To: jim.granville@designtools.co.nz Organization: Mandeno Granville elect X-Mailer: Mozilla 3.0C-XTRA (Win95; I) MIME-Version: 1.0 Newsgroups: comp.arch.fpga Subject: Re: FPGA comes with a DAC? References: <3d7d3d4d@news.starhub.net.sg> <6u7kht5vv0.fsf@chonsp.franklin.ch> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 30 Date: Wed, 11 Sep 2002 10:45:47 +1200 NNTP-Posting-Host: 203.79.98.250 X-Complaints-To: abuse@tsnz.net X-Trace: news02.tsnz.net 1031698085 203.79.98.250 (Wed, 11 Sep 2002 10:48:05 NZST) NNTP-Posting-Date: Wed, 11 Sep 2002 10:48:05 NZST Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!out.nntp.be!propagator-SanJose!news-in-sanjose!cyclone-sf.pbi.net!216.218.192.242!news.he.net!news-out.spamkiller.net!propagator-maxim!news-in.spamkiller.net!news02.tsnz.net!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:20849 Neil Franklin wrote: > > "Cool Morning ..." writes: > > > I am looking for an FPGA chip which has a built-in DAC. My intend > > it to build a portable with three chips only, A compact-flash, an FPGA > > containing the MP3 decoder > > > > What's the SIMPLEST approach possible to make a portable MP3 player > > in today's technology? > > With ->ANY<- FPGA you can implement an Sigma-Delta DAC in the FPGAs > normal logic gates. So I doubt you will find an FPGA with hardwired > DAC circuits. > > Specific for Virtex: http://www.xilinx.com/xapp/xapp154.pdf > > They there show an minimal FPGA+R+C circuit. For audio you will need > an second R parallel to the C (acts with first R as voltage divider > 3.3->0.12V) and possibly an second C after the R-C connection point > (to get rid of DC component, depends on your amplifier chip). You would also benefit from feeding the pulse stream through a TinyLogic gate, with special clean supply rails. The GND and VCC noise on a FPGA is unlikely to give a viable audio noise floor. Any Vcc/Gnd noise is fed straight thru the RC integrator, and this is internal (noisier) vcc.gnd, not the pins. -jg ###### From: allan_herriman.hates.spam@agilent.com (Allan Herriman) Newsgroups: comp.arch.fpga Subject: Re: FPGA comes with a DAC? Date: Wed, 11 Sep 2002 05:19:01 GMT Organization: Agilent Technologies Lines: 29 Message-ID: <3d7ed09a.177398836@netnews.agilent.com> References: <3d7d3d4d@news.starhub.net.sg> <6u7kht5vv0.fsf@chonsp.franklin.ch> NNTP-Posting-Host: cswreg.cos.agilent.com X-Trace: cswtrans.cos.agilent.com 1031721540 25334 130.29.154.45 (11 Sep 2002 05:19:00 GMT) X-Complaints-To: usenet@cswtrans.cos.agilent.com NNTP-Posting-Date: Wed, 11 Sep 2002 05:19:00 +0000 (UTC) X-Newsreader: Forte Free Agent 1.21/32.243 Cache-Post-Path: cswreg.cos.agilent.com!unknown@hpiw0398.aus.agilent.com X-Cache: nntpcache 2.3.3 (see http://www.nntpcache.org/) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!enews.sgi.com!sdd.hp.com!agilent.com!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:20855 On 11 Sep 2002 00:21:39 +0200, Neil Franklin wrote: >"Cool Morning ..." writes: > >> I am looking for an FPGA chip which has a built-in DAC. My intend >> it to build a portable with three chips only, A compact-flash, an FPGA >> containing the MP3 decoder >> >> What's the SIMPLEST approach possible to make a portable MP3 player >> in today's technology? > >With ->ANY<- FPGA you can implement an Sigma-Delta DAC in the FPGAs >normal logic gates. So I doubt you will find an FPGA with hardwired >DAC circuits. > >Specific for Virtex: http://www.xilinx.com/xapp/xapp154.pdf > >They there show an minimal FPGA+R+C circuit. For audio you will need >an second R parallel to the C (acts with first R as voltage divider >3.3->0.12V) and possibly an second C after the R-C connection point >(to get rid of DC component, depends on your amplifier chip). For audio you need a different DAC (despite what the app note says). XAPP154 describes a first order delta sigma modulator. Audio usually uses at least a second order modulator. Regards, Allan. ###### From: James Horn Newsgroups: comp.arch.fpga Subject: Re: FPGA comes with a DAC? Date: 11 Sep 2002 10:32:01 -0700 Organization: SVN.NET (www.svn.net) Lines: 17 Message-ID: <3d7f7e11@news.svn.net> References: <3d7d3d4d@news.starhub.net.sg> NNTP-Posting-Host: news.svn.net X-Trace: nnrp.atgi.net 1031765491 13579 64.40.160.12 (11 Sep 2002 17:31:31 GMT) X-Complaints-To: abuse@atgi.net NNTP-Posting-Date: Wed, 11 Sep 2002 17:31:31 +0000 (UTC) User-Agent: tin/1.4.5-20010409 ("One More Nightmare") (UNIX) (Linux/2.4.19 (i686)) X-Original-NNTP-Posting-Host: 64.40.160.10 X-Original-Trace: 11 Sep 2002 10:32:01 -0700, 64.40.160.10 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.imp.ch!news.imp.ch!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!HSNX.atgi.net!nnrp.atgi.net!news.svn.net!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:20864 Actually, given the complexity of MP3 decoding, the cost of the likely FPGA chip (and power for it), the need to configure the FPGA (i.e. another configuration memory or control chip), the need to clean up the digital noise from the DAC output... Why not use one of the many DSPs with on-board DACs? That's what they're designed for. You can also load the FPGA with the firmware for not only MP3 but OggVorbis and other audio formats as well. Your cell phone works that way - and not by coincidence. Just a thought... Jim Horn (I use FPGAs every day - and CPUs, DSPs, etc.) ###### From: "Lorenzo Lutti" Newsgroups: comp.arch.fpga References: <3d7d3d4d@news.starhub.net.sg> <6u7kht5vv0.fsf@chonsp.franklin.ch> Subject: Re: FPGA comes with a DAC? Lines: 18 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Message-ID: Date: Thu, 12 Sep 2002 19:08:03 GMT NNTP-Posting-Host: 151.38.59.226 X-Complaints-To: abuse@net24.it X-Trace: twister1.libero.it 1031857683 151.38.59.226 (Thu, 12 Sep 2002 21:08:03 MET DST) NNTP-Posting-Date: Thu, 12 Sep 2002 21:08:03 MET DST Organization: [Infostrada] Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!nntp.infostrada.it!twister1.libero.it.POSTED!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:20894 "Neil Franklin" ha scritto nel messaggio news:6u7kht5vv0.fsf@chonsp.franklin.ch... > So I doubt you will find an FPGA with > hardwired DAC circuits. There are the FPAAs, or "analog FPGA". For example: www.anadigm.com By the way, has anyone used this kind of devices? I'm not even able to download their trial software (the connection is always reset before the end, and after few retries their web server apparently bans my IP). -- Lorenzo ###### Message-ID: <3D81BC55.AD708685@oce.nl> Date: Fri, 13 Sep 2002 12:22:13 +0200 From: Dennis Sneijers X-Mailer: Mozilla 4.61 [en]C-CCK-MCD (Win95; I) X-Accept-Language: en,nl MIME-Version: 1.0 Newsgroups: comp.arch.fpga Subject: Re: FPGA comes with a DAC? References: <3d7d3d4d@news.starhub.net.sg> <6u7kht5vv0.fsf@chonsp.franklin.ch> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Organization: Oce Technologies B.V. Cache-Post-Path: news-ext.oce.nl!unknown@pc2-rjjb.oce.nl X-Cache: nntpcache 3.0.1 (see http://www.nntpcache.org/) Lines: 27 NNTP-Posting-Host: 134.188.145.119 X-Trace: 1031912442 oce.news.eu.uu.net 220 134.188.145.119 X-Complaints-To: abuse@oce.nl Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.imp.ch!news.imp.ch!newsfeed.vmunix.org!newsfeed.wirehub.nl!bnewspeer00.bru.ops.eu.uu.net!bnewspost00.bru.ops.eu.uu.net!emea.uu.net!oce.news.eu.uu.net!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:20943 The ispPAC20 & 30 do also have DAC's. Also analogue programmable devices. Furthermore i havn't used these devices but i am doing research at it right now. So if anyone could send me good information or user experiences are very welcome tnx dennis sneijers, the netherlands Lorenzo Lutti wrote: > > "Neil Franklin" ha scritto nel messaggio > news:6u7kht5vv0.fsf@chonsp.franklin.ch... > > > So I doubt you will find an FPGA with > > hardwired DAC circuits. > > There are the FPAAs, or "analog FPGA". For example: > > www.anadigm.com > > By the way, has anyone used this kind of devices? I'm not even able to > download their trial software (the connection is always reset before the > end, and after few retries their web server apparently bans my IP). > > -- > Lorenzo