From mbrennan@cern.ch Tue Aug 08 01:06:04 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cern!mbrennan From: mbrennan@cern.ch (Mateo Brennan) Newsgroups: comp.dsp Subject: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Aug08.010604.1724@cern.ch> Date: Tue, 08 Aug 1995 01:06:04 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] 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. Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm. -- Mateo Brennan *PLONK* filter active for trolls. Amiga 3000T - NetBSD 1.0 From bkim@mindspring.com Thu Aug 10 03:06:04 1995 Path: ashpoly!cascade!bigsur!mindspring!bkim From: bkim@mindspring.com (Brian Kim) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Aug10.030604.7887@mindspring.com> Date: Thu, 10 Aug 1995 03:06:04 GMT References: <1995Aug08.010604.1724@cern.ch> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Aug08.010604.1724@cern.ch>, mbrennan@cern.ch (Mateo Brennan) 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. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Brian Kim | bkim@mindspring.com PGP Key fingerprint: 0767 958D 4A1C FFF6 "Keep the channels open."