From eivanov@uu.net Wed Nov 13 07:25:00 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!uu!eivanov From: eivanov@uu.net (Elaine Ivanov) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Nov13.072500.8236@uu.net> Date: Wed, 13 Nov 1996 07:25:00 GMT Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: WinVN 0.99.5 Lines: 11 Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample. Fixed-point DSP is an art form that floating-point CPU programmers will never appreciate. -- Elaine Ivanov Opinions expressed are solely my own and not those of UUNET Technologies, Falls Church VA. ------------------------------------------------------------ From mlee@cmu.edu Wed Nov 13 13:52:00 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cmu!mlee From: mlee@cmu.edu (Mikhail Lee) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Nov13.135200.2552@cmu.edu> Date: Wed, 13 Nov 1996 13:52:00 GMT References: <1996Nov13.072500.8236@uu.net> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Nov13.072500.8236@uu.net>, eivanov@uu.net (Elaine Ivanov) writes: > Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. > This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Mikhail Lee *PLONK* filter active for trolls. Atari TT030 - NetBSD 1.0 From lnovak@cmu.edu Thu Nov 14 17:29:00 1996 Path: ashpoly!cascade!mxgate!coyoacan!cmu!lnovak From: lnovak@cmu.edu (Lucia Novak) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Nov14.172900.6762@cmu.edu> Date: Thu, 14 Nov 1996 17:29:00 GMT References: <1996Nov13.072500.8236@uu.net> <1996Nov13.135200.2552@cmu.edu> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1996Nov13.135200.2552@cmu.edu>, mlee@cmu.edu (Mikhail Lee) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. If you are posting from AOL, please read RFC 1036 before posting again. -- Lucia Novak *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From msouza@uni-hamburg.de Sat Nov 16 07:06:00 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!uni-hamburg!msouza From: msouza@uni-hamburg.de (Mikhail Souza) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Nov16.070600.7185@uni-hamburg.de> Date: Sat, 16 Nov 1996 07:06:00 GMT References: <1996Nov13.072500.8236@uu.net> <1996Nov13.135200.2552@cmu.edu> <1996Nov14.172900.6762@cmu.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Nov14.172900.6762@cmu.edu>, lnovak@cmu.edu (Lucia Novak) writes: > Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. > If you are posting from AOL, please read RFC 1036 before posting again. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Mikhail Souza Tape trading list upon request. SASE required for international mail. From jkowalski@pipeline.com Mon Nov 18 04:09:00 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!pipeline!jkowalski From: jkowalski@pipeline.com (Joachim Kowalski) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Nov18.040900.7519@pipeline.com> Date: Mon, 18 Nov 1996 04:09:00 GMT References: <1996Nov13.072500.8236@uu.net> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1996Nov13.072500.8236@uu.net>, eivanov@uu.net (Elaine Ivanov) writes: > Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. > This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Joachim Kowalski Zyxel U-1496E @ 33,600 bps "The hatch is open. Is anyone listening?"