From mlaurent@pipeline.com Thu Jun 13 15:23:06 1996
Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!mlaurent
From: mlaurent@pipeline.com (Marisol Laurent)
Newsgroups: comp.dsp
Subject: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Jun13.152306.4231@pipeline.com>
Date: Thu, 13 Jun 1996 15:23:06 GMT
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Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip.

By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample.
This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks.

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

-- 
Marisol Laurent -- The Pipeline Internet Network
"Do not worship the copy."

From hlee@panix.com Sat Jun 15 09:22:06 1996
Path: ashpoly!cascade!brgate!saturno!panix!hlee
From: hlee@panix.com (Hana Lee)
Newsgroups: comp.dsp
Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1996Jun15.092206.3592@panix.com>
Date: Sat, 15 Jun 1996 09:22:06 GMT
References: <1996Jun13.152306.4231@pipeline.com>
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In article <1996Jun13.152306.4231@pipeline.com>, mlaurent@pipeline.com (Marisol Laurent) writes:
> Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip.

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

-- 
Hana Lee
Tape trading list upon request. SASE required for international mail.