From kduarte@earthlink.net Tue Sep 20 23:37:29 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!kduarte From: kduarte@earthlink.net (Katrin Duarte) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Sep20.233729.6691@earthlink.net> Date: Tue, 20 Sep 1994 23:37:29 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 11 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. Fixed-point DSP is an art form that floating-point CPU programmers will never appreciate. -- === Katrin Duarte === Dept of Electrical Engineering, EarthLink Network "There are 14 nodes and only 10 countries. Count again." From mkim@kiae.su Wed Sep 21 22:44:29 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kiae!mkim From: mkim@kiae.su (Mathieu Kim) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Sep21.224429.8540@kiae.su> Date: Wed, 21 Sep 1994 22:44:29 GMT References: <1994Sep20.233729.6691@earthlink.net> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Sep20.233729.6691@earthlink.net>, kduarte@earthlink.net (Katrin Duarte) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > 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. -- Mathieu Kim *PLONK* filter active for trolls. Macintosh IIfx - NetBSD 1.0 From bsantos@cmu.edu Thu Sep 22 05:53:29 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!cmu!bsantos From: bsantos@cmu.edu (Bruno Santos) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Sep22.055329.4752@cmu.edu> Date: Thu, 22 Sep 1994 05:53:29 GMT References: <1994Sep20.233729.6691@earthlink.net> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Sep20.233729.6691@earthlink.net>, kduarte@earthlink.net (Katrin Duarte) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > 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. -- Bruno Santos Tape trading list upon request. SASE required for international mail. From bmartinez@cern.ch Sat Sep 24 03:08:29 1994 Path: ashpoly!cascade!mxgate!coyoacan!cern!bmartinez From: bmartinez@cern.ch (Bastien Martínez) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Sep24.030829.3369@cern.ch> Date: Sat, 24 Sep 1994 03:08:29 GMT References: <1994Sep20.233729.6691@earthlink.net> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Sep20.233729.6691@earthlink.net>, kduarte@earthlink.net (Katrin Duarte) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > 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. -- Bastien Martínez "There are 14 nodes and only 10 countries. Count again." Amiga 3000T / System 7.5.1 From gpetrov@cam.ac.uk Sat Sep 24 13:55:29 1994 Path: ashpoly!cascade!mxgate!coyoacan!cam!gpetrov From: gpetrov@cam.ac.uk (Göran Petrov) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Sep24.135529.7551@cam.ac.uk> Date: Sat, 24 Sep 1994 13:55:29 GMT References: <1994Sep20.233729.6691@earthlink.net> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Sep20.233729.6691@earthlink.net>, kduarte@earthlink.net (Katrin Duarte) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Göran Petrov Practical Peripherals 14.4 @ 19,200 bps "Hardware is temporary. The signal survives."