From srobertson@clari.net Sun Dec 10 11:32:52 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!clari!srobertson
From: srobertson@clari.net (Sun-mi Robertson)
Newsgroups: comp.dsp
Subject: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Dec10.113252.5248@clari.net>
Date: Sun, 10 Dec 1995 11:32:52 GMT
Organization: ClariNet Communications Corp
NNTP-Posting-Host: clari.net
X-Newsreader: TIN [version 1.2 PL2]
Lines: 11

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.
However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop.

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

-- 
Sun-mi Robertson
Opinions expressed are solely my own and not those of ClariNet Communications Corp.
------------------------------------------------------------

From rsato@pipeline.com Mon Dec 11 00:16:52 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!pipeline!rsato
From: rsato@pipeline.com (Renata Sato)
Newsgroups: comp.dsp
Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Dec11.001652.5563@pipeline.com>
Date: Mon, 11 Dec 1995 00:16:52 GMT
References: <1995Dec10.113252.5248@clari.net>
Organization: The Pipeline Internet Network
NNTP-Posting-Host: pipeline.com
X-Newsreader: NewsWatcher 2.0b24
Lines: 11

In article <1995Dec10.113252.5248@clari.net>, srobertson@clari.net (Sun-mi Robertson) writes:
> Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems.

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

Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin!

-- 
Renata Sato | rsato@pipeline.com
PGP Key fingerprint: 5A72 AE53 D884 C081
"Keep the channels open."

From msanchez@uni-hamburg.de Tue Dec 12 02:30:52 1995
Path: ashpoly!cascade!bigsur!uni-hamburg!msanchez
From: msanchez@uni-hamburg.de (Mei Sánchez)
Newsgroups: comp.dsp
Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Dec12.023052.1113@uni-hamburg.de>
Date: Tue, 12 Dec 1995 02:30:52 GMT
References: <1995Dec10.113252.5248@clari.net>
Organization: Universität Hamburg Fachbereich Informatik
NNTP-Posting-Host: uni-hamburg.de
X-Newsreader: TIN [version 1.2 PL2]
Lines: 10

In article <1995Dec10.113252.5248@clari.net>, srobertson@clari.net (Sun-mi Robertson) 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.

-- 
Mei Sánchez | msanchez@uni-hamburg.de
PGP Key fingerprint: 13F3 574A 5263 E304
"Keep the channels open."

From sweber@mindspring.com Tue Dec 12 03:55:52 1995
Path: ashpoly!cascade!brgate!saturno!mindspring!sweber
From: sweber@mindspring.com (Steve Weber)
Newsgroups: comp.dsp
Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Dec12.035552.6214@mindspring.com>
Date: Tue, 12 Dec 1995 03:55:52 GMT
References: <1995Dec10.113252.5248@clari.net> <1995Dec12.023052.1113@uni-hamburg.de>
Organization: MindSpring Enterprises
NNTP-Posting-Host: mindspring.com
X-Newsreader: TIN [version 1.2 PL2]
Lines: 8

In article <1995Dec12.023052.1113@uni-hamburg.de>, msanchez@uni-hamburg.de (Mei Sánchez) writes:
> Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in.

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

-- 
Steve Weber -- MindSpring Enterprises
"In theory there is no difference between theory and practice."

From mperez@mit.edu Tue Dec 12 20:52:52 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!mit!mperez
From: mperez@mit.edu (Min-jun Pérez)
Newsgroups: comp.dsp
Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Dec12.205252.8060@mit.edu>
Date: Tue, 12 Dec 1995 20:52:52 GMT
References: <1995Dec10.113252.5248@clari.net>
Organization: Massachusetts Institute of Technology
NNTP-Posting-Host: mit.edu
X-Newsreader: NewsWatcher 2.0b24
Lines: 9

In article <1995Dec10.113252.5248@clari.net>, srobertson@clari.net (Sun-mi Robertson) writes:
> Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems.

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

-- 
Min-jun Pérez
Opinions expressed are solely my own and not those of Massachusetts Institute of Technology.
------------------------------------------------------------