From msilva@titech.ac.jp Thu Mar 09 19:27:12 1995 Path: ashpoly!cascade!brgate!saturno!titech!msilva From: msilva@titech.ac.jp (Min-jun Silva) Newsgroups: comp.dsp Subject: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar09.192712.3114@titech.ac.jp> Date: Thu, 09 Mar 1995 19:27:12 GMT Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 10 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. However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip? -- Min-jun Silva Tape trading list upon request. SASE required for international mail. From lrobertson@purdue.edu Fri Mar 10 00:35:12 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!purdue!lrobertson From: lrobertson@purdue.edu (Liam Robertson) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar10.003512.7844@purdue.edu> Date: Fri, 10 Mar 1995 00:35:12 GMT References: <1995Mar09.192712.3114@titech.ac.jp> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Mar09.192712.3114@titech.ac.jp>, msilva@titech.ac.jp (Min-jun Silva) writes: > Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Liam Robertson *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0 From dpetrov@stanford.edu Sat Mar 11 13:38:12 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!stanford!dpetrov From: dpetrov@stanford.edu (Dmitri Petrov) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar11.133812.5367@stanford.edu> Date: Sat, 11 Mar 1995 13:38:12 GMT References: <1995Mar09.192712.3114@titech.ac.jp> <1995Mar10.003512.7844@purdue.edu> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Mar10.003512.7844@purdue.edu>, lrobertson@purdue.edu (Liam Robertson) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Dmitri Petrov *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0 From ofournier@panix.com Mon Mar 13 04:20:12 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!panix!ofournier From: ofournier@panix.com (Olga Fournier) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar13.042012.7478@panix.com> Date: Mon, 13 Mar 1995 04:20:12 GMT References: <1995Mar09.192712.3114@titech.ac.jp> <1995Mar10.003512.7844@purdue.edu> <1995Mar11.133812.5367@stanford.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Mar11.133812.5367@stanford.edu>, dpetrov@stanford.edu (Dmitri Petrov) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit! Top-posters will be placed in my ~/.killfile without notice. -- Olga Fournier | ofournier@panix.com PGP Key fingerprint: CAFE 1B7E 2EB2 0D3E "Keep the channels open." From lsouza@unam.mx Tue Mar 14 08:10:12 1995 Path: ashpoly!cascade!bigsur!unam!lsouza From: lsouza@unam.mx (Lucia Souza) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar14.081012.2170@unam.mx> Date: Tue, 14 Mar 1995 08:10:12 GMT References: <1995Mar09.192712.3114@titech.ac.jp> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Mar09.192712.3114@titech.ac.jp>, msilva@titech.ac.jp (Min-jun Silva) writes: > 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. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Lucia Souza *PLONK* filter active for trolls. 486DX2/66 (Linux 1.2.13) - NetBSD 1.0