From sandersson@kth.se Fri Jul 21 22:51:23 1995 Path: ashpoly!cascade!bigsur!kth!sandersson From: sandersson@kth.se (Sven Andersson) Newsgroups: comp.dsp Subject: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul21.225123.3088@kth.se> Date: Fri, 21 Jul 1995 22:51:23 GMT Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: Netscape 1.1N Lines: 11 Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. 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. Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip? -- Sven Andersson Zyxel U-1496E @ 28,800 bps "We don't sign stars. We build them." From njohansson@u-tokyo.ac.jp Sun Jul 23 00:52:23 1995 Path: ashpoly!cascade!mxgate!coyoacan!u-tokyo!njohansson From: njohansson@u-tokyo.ac.jp (Nadine Johansson) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul23.005223.1326@u-tokyo.ac.jp> Date: Sun, 23 Jul 1995 00:52:23 GMT References: <1995Jul21.225123.3088@kth.se> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jul21.225123.3088@kth.se>, sandersson@kth.se (Sven Andersson) writes: > Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. > By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Nadine Johansson -- University of Tokyo Department of Information Science "The carrier frequency does not drift by accident." From nmuller@kiae.su Sun Jul 23 22:54:23 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!kiae!nmuller From: nmuller@kiae.su (Nadine Müller) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul23.225423.5224@kiae.su> Date: Sun, 23 Jul 1995 22:54:23 GMT References: <1995Jul21.225123.3088@kth.se> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jul21.225123.3088@kth.se>, sandersson@kth.se (Sven Andersson) 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. -- Nadine Müller "There are 14 nodes and only 10 countries. Count again." Decstation 5000/200 / TOS 4.04 From hmuller@kth.se Tue Jul 25 19:12:23 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!kth!hmuller From: hmuller@kth.se (Hana Müller) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul25.191223.6989@kth.se> Date: Tue, 25 Jul 1995 19:12:23 GMT References: <1995Jul21.225123.3088@kth.se> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jul21.225123.3088@kth.se>, sandersson@kth.se (Sven Andersson) 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. -- Hana Müller Opinions expressed are solely my own and not those of Royal Institute of Technology, Stockholm. ------------------------------------------------------------