From jlaurent@uu.net Sat Dec 10 12:39:05 1994 Path: ashpoly!cascade!brgate!saturno!uu!jlaurent From: jlaurent@uu.net (Jen Laurent) Newsgroups: comp.dsp Subject: WTB/WTT: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Dec10.123905.1119@uu.net> Date: Sat, 10 Dec 1994 12:39:05 GMT Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.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? -- Jen Laurent "A soul is not exclusive to biology." 486DX2/66 (Linux 1.2.13) / System 7.5.1 From jpopov@uu.net Mon Dec 12 15:17:05 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!uu!jpopov From: jpopov@uu.net (Joachim Popov) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Dec12.151705.9175@uu.net> Date: Mon, 12 Dec 1994 15:17:05 GMT References: <1994Dec10.123905.1119@uu.net> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1994Dec10.123905.1119@uu.net>, jlaurent@uu.net (Jen Laurent) 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- === Joachim Popov === Dept of Electrical Engineering, UUNET Technologies, Falls Church VA "Tape doesn't lie at 02:14. Ears do." From lsanchez@earthlink.net Wed Dec 14 12:31:05 1994 Path: ashpoly!cascade!mxgate!coyoacan!earthlink!lsanchez From: lsanchez@earthlink.net (Lucia Sánchez) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Dec14.123105.7033@earthlink.net> Date: Wed, 14 Dec 1994 12:31:05 GMT References: <1994Dec10.123905.1119@uu.net> <1994Dec12.151705.9175@uu.net> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: Netscape 1.1N Lines: 11 In article <1994Dec12.151705.9175@uu.net>, jpopov@uu.net (Joachim Popov) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Lucia Sánchez Tape trading list upon request. SASE required for international mail. From ntakahashi@delphi.com Fri Dec 16 03:36:05 1994 Path: ashpoly!cascade!transat!ukc!fennimore!delphi!ntakahashi From: ntakahashi@delphi.com (Natalia Takahashi) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Dec16.033605.8718@delphi.com> Date: Fri, 16 Dec 1994 03:36:05 GMT References: <1994Dec10.123905.1119@uu.net> <1994Dec12.151705.9175@uu.net> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Dec12.151705.9175@uu.net>, jpopov@uu.net (Joachim Popov) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Natalia Takahashi *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0