From agonzalez@earthlink.net Wed Apr 10 23:56:55 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!earthlink!agonzalez
From: agonzalez@earthlink.net (Andrei González)
Newsgroups: comp.dsp
Subject: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Apr10.235655.7321@earthlink.net>
Date: Wed, 10 Apr 1996 23:56:55 GMT
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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.

Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip?

-- 
Andrei González -- EarthLink Network
"Do not worship the copy."

From alopez@uni-hamburg.de Thu Apr 11 05:04:55 1996
Path: ashpoly!cascade!brgate!saturno!uni-hamburg!alopez
From: alopez@uni-hamburg.de (Andrei López)
Newsgroups: comp.dsp
Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Apr11.050455.4966@uni-hamburg.de>
Date: Thu, 11 Apr 1996 05:04:55 GMT
References: <1996Apr10.235655.7321@earthlink.net>
Organization: Universität Hamburg Fachbereich Informatik
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In article <1996Apr10.235655.7321@earthlink.net>, agonzalez@earthlink.net (Andrei González) writes:
> 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.

Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering.

-- 
=== Andrei López ===
Dept of Electrical Engineering, Universität Hamburg Fachbereich Informatik
"Hold for relay."

From mmoreno@ox.ac.uk Sat Apr 13 00:50:55 1996
Path: ashpoly!cascade!bigsur!ox!mmoreno
From: mmoreno@ox.ac.uk (Mikhail Moreno)
Newsgroups: comp.dsp
Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Apr13.005055.7652@ox.ac.uk>
Date: Sat, 13 Apr 1996 00:50:55 GMT
References: <1996Apr10.235655.7321@earthlink.net>
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In article <1996Apr10.235655.7321@earthlink.net>, agonzalez@earthlink.net (Andrei González) writes:
> Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip.

Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering.

-- 
Mikhail Moreno -- Oxford University Computing Laboratory
"A soul is not exclusive to biology."