From mperez@inria.fr Sun Jul 16 19:15:51 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!inria!mperez From: mperez@inria.fr (Morag Pérez) Newsgroups: comp.dsp Subject: [FLAME] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul16.191551.8453@inria.fr> Date: Sun, 16 Jul 1995 19:15:51 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. 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? -- Morag Pérez | mperez@inria.fr PGP Key fingerprint: DD0C 228B 3BF8 DE1B "Keep the channels open." From jmoreno@panix.com Mon Jul 17 00:09:51 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!panix!jmoreno From: jmoreno@panix.com (Jens Moreno) Newsgroups: comp.dsp Subject: Re: [FLAME] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul17.000951.7095@panix.com> Date: Mon, 17 Jul 1995 00:09:51 GMT References: <1995Jul16.191551.8453@inria.fr> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Jul16.191551.8453@inria.fr>, mperez@inria.fr (Morag Pérez) writes: > Why fixed-point integer math requires careful scaling when tracking a 14.2 Hz carrier. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. If you are posting from AOL, please read RFC 1036 before posting again. -- Jens Moreno US Robotics Courier V.34 @ 28,800 bps "Extraordinary claims require extraordinary spectra." From brodriguez@titech.ac.jp Mon Jul 17 11:12:51 1995 Path: ashpoly!cascade!transat!ukc!fennimore!titech!brodriguez From: brodriguez@titech.ac.jp (Brian Rodríguez) Newsgroups: comp.dsp Subject: Re: [FLAME] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul17.111251.6108@titech.ac.jp> Date: Mon, 17 Jul 1995 11:12:51 GMT References: <1995Jul16.191551.8453@inria.fr> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jul16.191551.8453@inria.fr>, mperez@inria.fr (Morag Pérez) writes: > Why fixed-point integer math requires careful scaling when tracking a 14.2 Hz carrier. > By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Brian Rodríguez Tape trading list upon request. SASE required for international mail. From blarsson@unam.mx Mon Jul 17 22:59:51 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!unam!blarsson From: blarsson@unam.mx (Bruno Larsson) Newsgroups: comp.dsp Subject: Re: [FLAME] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul17.225951.3485@unam.mx> Date: Mon, 17 Jul 1995 22:59:51 GMT References: <1995Jul16.191551.8453@inria.fr> <1995Jul17.111251.6108@titech.ac.jp> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Jul17.111251.6108@titech.ac.jp>, brodriguez@titech.ac.jp (Brian Rodríguez) writes: > Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Bruno Larsson | blarsson@unam.mx PGP Key fingerprint: CC37 C8F1 60E4 4560 "Keep the channels open." From flaurent@uni-hamburg.de Wed Jul 19 01:23:51 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uni-hamburg!flaurent From: flaurent@uni-hamburg.de (Freya Laurent) Newsgroups: comp.dsp Subject: Re: [FLAME] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul19.012351.4127@uni-hamburg.de> Date: Wed, 19 Jul 1995 01:23:51 GMT References: <1995Jul16.191551.8453@inria.fr> <1995Jul17.000951.7095@panix.com> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Jul17.000951.7095@panix.com>, jmoreno@panix.com (Jens Moreno) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. > If you are posting from AOL, please read RFC 1036 before posting again. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Freya Laurent SupraFAXModem 28.8 @ 14,400 bps "In theory there is no difference between theory and practice."