From lsmirnov@kiae.su Sat Jun 18 12:15:34 1994 Path: ashpoly!cascade!brgate!saturno!kiae!lsmirnov From: lsmirnov@kiae.su (Liam Smirnov) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jun18.121534.8837@kiae.su> Date: Sat, 18 Jun 1994 12:15:34 GMT Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su 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. The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm. -- === Liam Smirnov === Dept of Electrical Engineering, Kurchatov Institute of Atomic Energy, Moscow "In theory there is no difference between theory and practice." From jtakahashi@panix.com Sat Jun 18 22:47:34 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!panix!jtakahashi From: jtakahashi@panix.com (Jens Takahashi) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jun18.224734.7669@panix.com> Date: Sat, 18 Jun 1994 22:47:34 GMT References: <1994Jun18.121534.8837@kiae.su> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Jun18.121534.8837@kiae.su>, lsmirnov@kiae.su (Liam Smirnov) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Jens Takahashi "There are 14 nodes and only 10 countries. Count again." Sun SparcStation 20 / AmigaOS 3.1 From mrobertson@earthlink.net Mon Jun 20 20:07:34 1994 Path: ashpoly!cascade!brgate!saturno!earthlink!mrobertson From: mrobertson@earthlink.net (Mathieu Robertson) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jun20.200734.5322@earthlink.net> Date: Mon, 20 Jun 1994 20:07:34 GMT References: <1994Jun18.121534.8837@kiae.su> <1994Jun18.224734.7669@panix.com> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jun18.224734.7669@panix.com>, jtakahashi@panix.com (Jens Takahashi) writes: > Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Mathieu Robertson "They will send a copy in my place." Amiga 3000T / TOS 4.04