From akuznetsov@uni-hamburg.de Tue Nov 07 11:23:47 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!uni-hamburg!akuznetsov From: akuznetsov@uni-hamburg.de (Astrid Kuznetsov) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Nov07.112347.3311@uni-hamburg.de> Date: Tue, 07 Nov 1995 11:23:47 GMT Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 Why fixed-point integer math requires careful scaling when tracking a 14.2 Hz carrier. The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip? -- Astrid Kuznetsov -- Universität Hamburg Fachbereich Informatik "Tape doesn't lie at 02:14. Ears do." From mwatanabe@netcom.com Wed Nov 08 05:39:47 1995 Path: ashpoly!cascade!bigsur!netcom!mwatanabe From: mwatanabe@netcom.com (Mei Watanabe) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Nov08.053947.3479@netcom.com> Date: Wed, 08 Nov 1995 05:39:47 GMT References: <1995Nov07.112347.3311@uni-hamburg.de> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Nov07.112347.3311@uni-hamburg.de>, akuznetsov@uni-hamburg.de (Astrid Kuznetsov) 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. -- Mei Watanabe *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From ssato@illinois.edu Thu Nov 09 21:05:47 1995 Path: ashpoly!cascade!transat!ukc!fennimore!illinois!ssato From: ssato@illinois.edu (Seo-yeon Sato) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Nov09.210547.4664@illinois.edu> Date: Thu, 09 Nov 1995 21:05:47 GMT References: <1995Nov07.112347.3311@uni-hamburg.de> <1995Nov08.053947.3479@netcom.com> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Nov08.053947.3479@netcom.com>, mwatanabe@netcom.com (Mei Watanabe) writes: > 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. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Seo-yeon Sato *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0