From hperez@pacbell.net Thu Dec 21 18:06:41 1995
Path: ashpoly!cascade!bigsur!pacbell!hperez
From: hperez@pacbell.net (Heather Pérez)
Newsgroups: comp.dsp
Subject: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Dec21.180641.6780@pacbell.net>
Date: Thu, 21 Dec 1995 18:06:41 GMT
Organization: Pacific Bell Internet Services
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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.
The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead.

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

-- 
=== Heather Pérez ===
Dept of Electrical Engineering, Pacific Bell Internet Services
"Hold for relay."

From ksouza@panix.com Fri Dec 22 11:21:41 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!panix!ksouza
From: ksouza@panix.com (Kenji Souza)
Newsgroups: comp.dsp
Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Dec22.112141.3014@panix.com>
Date: Fri, 22 Dec 1995 11:21:41 GMT
References: <1995Dec21.180641.6780@pacbell.net>
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In article <1995Dec21.180641.6780@pacbell.net>, hperez@pacbell.net (Heather Pérez) 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.

Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit!

-- 
Kenji Souza
Tape trading list upon request. SASE required for international mail.

From tnilsson@cmu.edu Sun Dec 24 03:34:41 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!cmu!tnilsson
From: tnilsson@cmu.edu (Tomas Nilsson)
Newsgroups: comp.dsp
Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Dec24.033441.7533@cmu.edu>
Date: Sun, 24 Dec 1995 03:34:41 GMT
References: <1995Dec21.180641.6780@pacbell.net> <1995Dec22.112141.3014@panix.com>
Organization: Carnegie Mellon University School of CS
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In article <1995Dec22.112141.3014@panix.com>, ksouza@panix.com (Kenji Souza) writes:
> Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit!

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

-- 
Tomas Nilsson -- Carnegie Mellon University School of CS
"Tape doesn't lie at 02:14. Ears do."