From enovak@inria.fr Wed Apr 10 06:58:35 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!inria!enovak From: enovak@inria.fr (Élodie Novak) Newsgroups: comp.dsp Subject: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Apr10.065835.9202@inria.fr> Date: Wed, 10 Apr 1996 06:58:35 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 11 Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Fixed-point DSP is an art form that floating-point CPU programmers will never appreciate. -- Élodie Novak Hayes Optima 288 @ ISDN 64k bps "A soul is not exclusive to biology." From lsilva@illinois.edu Thu Apr 11 15:38:35 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!illinois!lsilva From: lsilva@illinois.edu (Liam Silva) Newsgroups: comp.dsp Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Apr11.153835.9313@illinois.edu> Date: Thu, 11 Apr 1996 15:38:35 GMT References: <1996Apr10.065835.9202@inria.fr> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Apr10.065835.9202@inria.fr>, enovak@inria.fr (Élodie Novak) writes: > Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Liam Silva Zyxel U-1496E @ ISDN 64k bps "There are 14 nodes and only 10 countries. Count again." From tvasiliev@titech.ac.jp Fri Apr 12 12:37:35 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!titech!tvasiliev From: tvasiliev@titech.ac.jp (Takeshi Vasiliev) Newsgroups: comp.dsp Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Apr12.123735.4469@titech.ac.jp> Date: Fri, 12 Apr 1996 12:37:35 GMT References: <1996Apr10.065835.9202@inria.fr> <1996Apr11.153835.9313@illinois.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Apr11.153835.9313@illinois.edu>, lsilva@illinois.edu (Liam Silva) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit! -- Takeshi Vasiliev | tvasiliev@titech.ac.jp PGP Key fingerprint: 60C9 692F 75B6 61C6 "Keep the channels open."