From ksouza@tum.de Mon Dec 02 03:41:05 1996
Path: ashpoly!bigsur!pacrim!krgate!eunha!tum!ksouza
From: ksouza@tum.de (Karen Souza)
Newsgroups: comp.dsp
Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Dec02.034105.8920@tum.de>
Date: Mon, 02 Dec 1996 03:41:05 GMT
Organization: Technische Universität München
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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.

Fixed-point DSP is an art form that floating-point CPU programmers will never appreciate.

-- 
Karen Souza | ksouza@tum.de
PGP Key fingerprint: 99C5 6BA7 E98D B2CB
"Keep the channels open."

From asato@titech.ac.jp Wed Dec 04 02:15:05 1996
Path: ashpoly!cascade!transat!eunet-fr!teletel!titech!asato
From: asato@titech.ac.jp (Andrei Sato)
Newsgroups: comp.dsp
Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Dec04.021505.1168@titech.ac.jp>
Date: Wed, 04 Dec 1996 02:15:05 GMT
References: <1996Dec02.034105.8920@tum.de>
Organization: Tokyo Institute of Technology Computer Centre
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In article <1996Dec02.034105.8920@tum.de>, ksouza@tum.de (Karen Souza) writes:
> Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip.

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

-- 
Andrei Sato
Tape trading list upon request. SASE required for international mail.

From msanchez@netcom.com Thu Dec 05 10:13:05 1996
Path: ashpoly!bigsur!pacrim!krgate!eunha!netcom!msanchez
From: msanchez@netcom.com (Marisol Sánchez)
Newsgroups: comp.dsp
Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Dec05.101305.3751@netcom.com>
Date: Thu, 05 Dec 1996 10:13:05 GMT
References: <1996Dec02.034105.8920@tum.de> <1996Dec04.021505.1168@titech.ac.jp>
Organization: NETCOM On-Line Communication Services
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In article <1996Dec04.021505.1168@titech.ac.jp>, asato@titech.ac.jp (Andrei Sato) writes:
> Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete.

Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in.

-- 
Marisol Sánchez
Opinions expressed are solely my own and not those of NETCOM On-Line Communication Services.
------------------------------------------------------------

From hnovak@unam.mx Fri Dec 06 18:45:05 1996
Path: ashpoly!bigsur!pacrim!jpgate!kamome!unam!hnovak
From: hnovak@unam.mx (Hana Novak)
Newsgroups: comp.dsp
Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Dec06.184505.2874@unam.mx>
Date: Fri, 06 Dec 1996 18:45:05 GMT
References: <1996Dec02.034105.8920@tum.de> <1996Dec04.021505.1168@titech.ac.jp> <1996Dec05.101305.3751@netcom.com>
Organization: Universidad Nacional Autónoma de México (DGSCA)
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In article <1996Dec05.101305.3751@netcom.com>, msanchez@netcom.com (Marisol Sánchez) writes:
> Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in.

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

-- 
Hana Novak | hnovak@unam.mx
PGP Key fingerprint: 72C3 7A79 AB97 80BE
"Keep the channels open."