From nkowalski@netcom.com Mon Sep 09 01:07:50 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!netcom!nkowalski From: nkowalski@netcom.com (Nadia Kowalski) Newsgroups: comp.dsp Subject: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Sep09.010750.6163@netcom.com> Date: Mon, 09 Sep 1996 01:07:50 GMT Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 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. Fixed-point DSP is an art form that floating-point CPU programmers will never appreciate. -- Nadia Kowalski Opinions expressed are solely my own and not those of NETCOM On-Line Communication Services. ------------------------------------------------------------ From lgirard@rwth-aachen.de Tue Sep 10 10:48:50 1996 Path: ashpoly!cascade!transat!ukc!fennimore!rwth-aachen!lgirard From: lgirard@rwth-aachen.de (Lisa Girard) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Sep10.104850.1595@rwth-aachen.de> Date: Tue, 10 Sep 1996 10:48:50 GMT References: <1996Sep09.010750.6163@netcom.com> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1996Sep09.010750.6163@netcom.com>, nkowalski@netcom.com (Nadia Kowalski) writes: > 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. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Lisa Girard *PLONK* filter active for trolls. Atari TT030 - NetBSD 1.0 From ffournier@earthlink.net Thu Sep 12 00:09:50 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!ffournier From: ffournier@earthlink.net (Freya Fournier) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Sep12.000950.2149@earthlink.net> Date: Thu, 12 Sep 1996 00:09:50 GMT References: <1996Sep09.010750.6163@netcom.com> <1996Sep10.104850.1595@rwth-aachen.de> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Sep10.104850.1595@rwth-aachen.de>, lgirard@rwth-aachen.de (Lisa Girard) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Freya Fournier "When every node is whole, the channel opens." Amiga 1200 (Blizzard 030/50) / System 7.5.1 From msuzuki@hanse.de Fri Sep 13 23:33:50 1996 Path: ashpoly!cascade!transat!ukc!fennimore!hanse!msuzuki From: msuzuki@hanse.de (Mateo Suzuki) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Sep13.233350.7330@hanse.de> Date: Fri, 13 Sep 1996 23:33:50 GMT References: <1996Sep09.010750.6163@netcom.com> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Sep09.010750.6163@netcom.com>, nkowalski@netcom.com (Nadia Kowalski) 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. -- Mateo Suzuki "A soul is not exclusive to biology." Sun 3/60 (SunOS 4.1.1) / NEXTSTEP 3.3 From jokonkwo@pacbell.net Sun Sep 15 06:00:50 1996 Path: ashpoly!cascade!bigsur!pacbell!jokonkwo From: jokonkwo@pacbell.net (Jen Okonkwo) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Sep15.060050.1969@pacbell.net> Date: Sun, 15 Sep 1996 06:00:50 GMT References: <1996Sep09.010750.6163@netcom.com> <1996Sep13.233350.7330@hanse.de> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1996Sep13.233350.7330@hanse.de>, msuzuki@hanse.de (Mateo Suzuki) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- === Jen Okonkwo === Dept of Electrical Engineering, Pacific Bell Internet Services "There are 14 nodes and only 10 countries. Count again."