From sdubois@kth.se Mon May 20 16:55:20 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kth!sdubois
From: sdubois@kth.se (Sergei Dubois)
Newsgroups: comp.dsp
Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996May20.165520.3193@kth.se>
Date: Mon, 20 May 1996 16:55:20 GMT
Organization: Royal Institute of Technology, Stockholm
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Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems.

By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample.
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?

-- 
Sergei Dubois
Opinions expressed are solely my own and not those of Royal Institute of Technology, Stockholm.
------------------------------------------------------------

From loliveira@panix.com Wed May 22 05:45:20 1996
Path: ashpoly!bigsur!pacrim!krgate!eunha!panix!loliveira
From: loliveira@panix.com (Lucia Oliveira)
Newsgroups: comp.dsp
Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996May22.054520.4235@panix.com>
Date: Wed, 22 May 1996 05:45:20 GMT
References: <1996May20.165520.3193@kth.se>
Organization: Public Access Unix of New York
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In article <1996May20.165520.3193@kth.se>, sdubois@kth.se (Sergei Dubois) writes:
> Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems.
> By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample.

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

-- 
Lucia Oliveira -- Public Access Unix of New York
"Measuring a record you own is listening, not piracy."