From enovak@inria.fr Sun Feb 19 20:52:27 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!inria!enovak From: enovak@inria.fr (Emi Novak) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb19.205227.6479@inria.fr> Date: Sun, 19 Feb 1995 20:52:27 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: NewsWatcher 2.0b24 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. 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. -- === Emi Novak === Dept of Electrical Engineering, INRIA Rocquencourt "Do not worship the copy." From flopez@pipeline.com Tue Feb 21 12:24:27 1995 Path: ashpoly!cascade!bigsur!pipeline!flopez From: flopez@pipeline.com (Fiona López) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb21.122427.6559@pipeline.com> Date: Tue, 21 Feb 1995 12:24:27 GMT References: <1995Feb19.205227.6479@inria.fr> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Feb19.205227.6479@inria.fr>, enovak@inria.fr (Emi Novak) 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. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Fiona López *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From amacdonald@netcom.com Thu Feb 23 05:18:27 1995 Path: ashpoly!cascade!transat!ukc!fennimore!netcom!amacdonald From: amacdonald@netcom.com (Aiko MacDonald) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb23.051827.9374@netcom.com> Date: Thu, 23 Feb 1995 05:18:27 GMT References: <1995Feb19.205227.6479@inria.fr> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Feb19.205227.6479@inria.fr>, enovak@inria.fr (Emi Novak) 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. -- Aiko MacDonald US Robotics Courier V.34 @ 33,600 bps "Marcus is not one man."