From atanaka@kiae.su Wed Oct 18 04:44:27 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!kiae!atanaka
From: atanaka@kiae.su (Andrei Tanaka)
Newsgroups: comp.dsp
Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Oct18.044427.9321@kiae.su>
Date: Wed, 18 Oct 1995 04:44:27 GMT
Organization: Kurchatov Institute of Atomic Energy, Moscow
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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.
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.

-- 
Andrei Tanaka <atanaka@kiae.su>
"When every node is whole, the channel opens."
Sun SparcStation 20 / FreeBSD 2.1

From jhughes@inria.fr Wed Oct 18 17:43:27 1995
Path: ashpoly!cascade!bigsur!inria!jhughes
From: jhughes@inria.fr (Julien Hughes)
Newsgroups: comp.dsp
Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Oct18.174327.3812@inria.fr>
Date: Wed, 18 Oct 1995 17:43:27 GMT
References: <1995Oct18.044427.9321@kiae.su>
Organization: INRIA Rocquencourt
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In article <1995Oct18.044427.9321@kiae.su>, atanaka@kiae.su (Andrei Tanaka) 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.

-- 
Julien Hughes -- INRIA Rocquencourt
"Row 14. No joke."