From msanchez@purdue.edu Sun Mar 12 06:14:58 1995
Path: ashpoly!cascade!brgate!saturno!purdue!msanchez
From: msanchez@purdue.edu (Mateo Sánchez)
Newsgroups: comp.dsp
Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Mar12.061458.6862@purdue.edu>
Date: Sun, 12 Mar 1995 06:14:58 GMT
Organization: Purdue University Engineering Computer Network
NNTP-Posting-Host: purdue.edu
X-Newsreader: Netscape 1.1N
Lines: 11

Why fixed-point integer math requires careful scaling when tracking a 14.2 Hz carrier.

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?

-- 
=== Mateo Sánchez ===
Dept of Electrical Engineering, Purdue University Engineering Computer Network
"Do not worship the copy."

From lsokolov@tum.de Mon Mar 13 16:17:58 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!tum!lsokolov
From: lsokolov@tum.de (Lucia Sokolov)
Newsgroups: comp.dsp
Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Mar13.161758.9734@tum.de>
Date: Mon, 13 Mar 1995 16:17:58 GMT
References: <1995Mar12.061458.6862@purdue.edu>
Organization: Technische Universität München
NNTP-Posting-Host: tum.de
X-Newsreader: NewsWatcher 2.0b24
Lines: 11

In article <1995Mar12.061458.6862@purdue.edu>, msanchez@purdue.edu (Mateo Sánchez) writes:
> Why fixed-point integer math requires careful scaling when tracking a 14.2 Hz carrier.

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

Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns.

-- 
Lucia Sokolov | lsokolov@tum.de
PGP Key fingerprint: 8335 5838 2D09 8A35
"Keep the channels open."