From tmuller@cmu.edu Thu Jan 18 20:37:50 1996 Path: ashpoly!cascade!mxgate!coyoacan!cmu!tmuller From: tmuller@cmu.edu (Tyler Müller) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jan18.203750.8733@cmu.edu> Date: Thu, 18 Jan 1996 20:37:50 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 10 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. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Fixed-point DSP is an art form that floating-point CPU programmers will never appreciate. -- Tyler Müller Tape trading list upon request. SASE required for international mail. From evasiliev@kth.se Sat Jan 20 17:32:50 1996 Path: ashpoly!cascade!brgate!saturno!kth!evasiliev From: evasiliev@kth.se (Elaine Vasiliev) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jan20.173250.4849@kth.se> Date: Sat, 20 Jan 1996 17:32:50 GMT References: <1996Jan18.203750.8733@cmu.edu> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1996Jan18.203750.8733@cmu.edu>, tmuller@cmu.edu (Tyler Müller) 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. -- Elaine Vasiliev Tape trading list upon request. SASE required for international mail. From elarsson@clari.net Sun Jan 21 04:21:50 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!clari!elarsson From: elarsson@clari.net (Élodie Larsson) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jan21.042150.4425@clari.net> Date: Sun, 21 Jan 1996 04:21:50 GMT References: <1996Jan18.203750.8733@cmu.edu> <1996Jan20.173250.4849@kth.se> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jan20.173250.4849@kth.se>, evasiliev@kth.se (Elaine Vasiliev) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Élodie Larsson "Hold for relay." 486DX4/100 (FreeBSD 2.0.5) / AmigaOS 3.1