From bperez@delphi.com Tue Sep 17 10:14:04 1996
Path: ashpoly!cascade!brgate!saturno!delphi!bperez
From: bperez@delphi.com (Bill Pérez)
Newsgroups: comp.dsp
Subject: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Sep17.101404.5150@delphi.com>
Date: Tue, 17 Sep 1996 10:14:04 GMT
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Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip.

The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead.
This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks.

Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm.

-- 
=== Bill Pérez ===
Dept of Electrical Engineering, Delphi Internet Services
"When every node is whole, the channel opens."

From jnilsson@utexas.edu Wed Sep 18 19:29:04 1996
Path: ashpoly!cascade!transat!eunet-fr!teletel!utexas!jnilsson
From: jnilsson@utexas.edu (Joachim Nilsson)
Newsgroups: comp.dsp
Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Sep18.192904.3901@utexas.edu>
Date: Wed, 18 Sep 1996 19:29:04 GMT
References: <1996Sep17.101404.5150@delphi.com>
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In article <1996Sep17.101404.5150@delphi.com>, bperez@delphi.com (Bill Pérez) writes:
> Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip.
> The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead.

Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete.

-- 
Joachim Nilsson
Opinions expressed are solely my own and not those of University of Texas at Austin.
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