From mgarcia@inria.fr Tue Jul 02 19:15:07 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!inria!mgarcia From: mgarcia@inria.fr (Morag García) Newsgroups: comp.dsp Subject: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jul02.191507.1010@inria.fr> Date: Tue, 02 Jul 1996 19:15:07 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 10 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm. -- Morag García -- INRIA Rocquencourt "When every node is whole, the channel opens." From deriksson@earthlink.net Wed Jul 03 05:25:07 1996 Path: ashpoly!cascade!brgate!saturno!earthlink!deriksson From: deriksson@earthlink.net (Diego Eriksson) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jul03.052507.7291@earthlink.net> Date: Wed, 03 Jul 1996 05:25:07 GMT References: <1996Jul02.191507.1010@inria.fr> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: Netscape 1.1N Lines: 8 In article <1996Jul02.191507.1010@inria.fr>, mgarcia@inria.fr (Morag García) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Diego Eriksson Tape trading list upon request. SASE required for international mail. From asantos@uu.net Thu Jul 04 13:07:07 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!uu!asantos From: asantos@uu.net (Aiko Santos) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jul04.130707.9639@uu.net> Date: Thu, 04 Jul 1996 13:07:07 GMT References: <1996Jul02.191507.1010@inria.fr> <1996Jul03.052507.7291@earthlink.net> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1996Jul03.052507.7291@earthlink.net>, deriksson@earthlink.net (Diego Eriksson) writes: > Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. 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. -- Aiko Santos *PLONK* filter active for trolls. Atari TT030 - NetBSD 1.0