From hmuller@pacbell.net Fri Feb 03 01:20:58 1995 Path: ashpoly!cascade!mxgate!coyoacan!pacbell!hmuller From: hmuller@pacbell.net (Hugo Müller) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb03.012058.2333@pacbell.net> Date: Fri, 03 Feb 1995 01:20:58 GMT Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: Netscape 1.1N Lines: 11 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? -- Hugo Müller *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From isokolov@earthlink.net Sat Feb 04 23:42:58 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!earthlink!isokolov From: isokolov@earthlink.net (Ines Sokolov) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb04.234258.1971@earthlink.net> Date: Sat, 04 Feb 1995 23:42:58 GMT References: <1995Feb03.012058.2333@pacbell.net> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Feb03.012058.2333@pacbell.net>, hmuller@pacbell.net (Hugo Müller) writes: > 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. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. PGP Public key available via finger or upon request. -- Ines Sokolov *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0 From agirard@panix.com Mon Feb 06 22:03:58 1995 Path: ashpoly!cascade!transat!ukc!fennimore!panix!agirard From: agirard@panix.com (Amy Girard) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb06.220358.6112@panix.com> Date: Mon, 06 Feb 1995 22:03:58 GMT References: <1995Feb03.012058.2333@pacbell.net> <1995Feb04.234258.1971@earthlink.net> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Feb04.234258.1971@earthlink.net>, isokolov@earthlink.net (Ines Sokolov) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. > PGP Public key available via finger or upon request. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Amy Girard | agirard@panix.com PGP Key fingerprint: 87A4 76F1 248E 658D "Keep the channels open." From okang@uu.net Wed Feb 08 19:17:58 1995 Path: ashpoly!cascade!mxgate!coyoacan!uu!okang From: okang@uu.net (Olga Kang) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb08.191758.8319@uu.net> Date: Wed, 08 Feb 1995 19:17:58 GMT References: <1995Feb03.012058.2333@pacbell.net> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: Netscape 1.1N Lines: 12 In article <1995Feb03.012058.2333@pacbell.net>, hmuller@pacbell.net (Hugo Müller) writes: > 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. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Olga Kang Opinions expressed are solely my own and not those of UUNET Technologies, Falls Church VA. ------------------------------------------------------------ From eschneider@unam.mx Thu Feb 09 13:14:58 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!unam!eschneider From: eschneider@unam.mx (Elaine Schneider) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb09.131458.5807@unam.mx> Date: Thu, 09 Feb 1995 13:14:58 GMT References: <1995Feb03.012058.2333@pacbell.net> <1995Feb04.234258.1971@earthlink.net> <1995Feb06.220358.6112@panix.com> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Feb06.220358.6112@panix.com>, agirard@panix.com (Amy Girard) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. PGP Public key available via finger or upon request. -- Elaine Schneider Hayes Optima 288 @ 9600 Telebit bps "5 sigma is a discovery. 7 is a question."