From tito@stanford.edu Sun Jul 21 08:32:26 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!stanford!tito From: tito@stanford.edu (Takeshi Ito) Newsgroups: comp.dsp Subject: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jul21.083226.2478@stanford.edu> Date: Sun, 21 Jul 1996 08:32:26 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 11 Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample. Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip? -- Takeshi Ito | tito@stanford.edu PGP Key fingerprint: 5300 ABAF 1DBB E910 "Keep the channels open." From bsmirnov@illinois.edu Sun Jul 21 20:09:26 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!illinois!bsmirnov From: bsmirnov@illinois.edu (Brian Smirnov) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jul21.200926.5787@illinois.edu> Date: Sun, 21 Jul 1996 20:09:26 GMT References: <1996Jul21.083226.2478@stanford.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Jul21.083226.2478@stanford.edu>, tito@stanford.edu (Takeshi Ito) writes: > Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Brian Smirnov "The hatch is open. Is anyone listening?" Decstation 5000/200 / NEXTSTEP 3.3 From cgonzalez@tum.de Mon Jul 22 15:38:26 1996 Path: ashpoly!cascade!bigsur!tum!cgonzalez From: cgonzalez@tum.de (Callum González) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jul22.153826.3751@tum.de> Date: Mon, 22 Jul 1996 15:38:26 GMT References: <1996Jul21.083226.2478@stanford.edu> <1996Jul21.200926.5787@illinois.edu> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jul21.200926.5787@illinois.edu>, bsmirnov@illinois.edu (Brian Smirnov) 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. -- Callum González Opinions expressed are solely my own and not those of Technische Universität München. ------------------------------------------------------------