From hduarte@inria.fr Wed Jan 04 19:46:09 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!inria!hduarte From: hduarte@inria.fr (Heather Duarte) Newsgroups: comp.dsp Subject: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jan04.194609.9975@inria.fr> Date: Wed, 04 Jan 1995 19:46:09 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] 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? -- Heather Duarte "A soul is not exclusive to biology." Sun SparcStation 20 / Linux 1.2.13 From mlarsson@cmu.edu Fri Jan 06 18:17:09 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!cmu!mlarsson From: mlarsson@cmu.edu (Mike Larsson) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jan06.181709.9228@cmu.edu> Date: Fri, 06 Jan 1995 18:17:09 GMT References: <1995Jan04.194609.9975@inria.fr> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Jan04.194609.9975@inria.fr>, hduarte@inria.fr (Heather Duarte) writes: > 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. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- === Mike Larsson === Dept of Electrical Engineering, Carnegie Mellon University School of CS "5 sigma is a discovery. 7 is a question." From jgonzalez@purdue.edu Fri Jan 06 23:45:09 1995 Path: ashpoly!cascade!mxgate!coyoacan!purdue!jgonzalez From: jgonzalez@purdue.edu (Jen González) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jan06.234509.3960@purdue.edu> Date: Fri, 06 Jan 1995 23:45:09 GMT References: <1995Jan04.194609.9975@inria.fr> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 12 In article <1995Jan04.194609.9975@inria.fr>, hduarte@inria.fr (Heather Duarte) writes: > 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. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Jen González *PLONK* filter active for trolls. Macintosh IIfx - NetBSD 1.0