From esantos@uu.net Thu Jun 15 01:50:24 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uu!esantos From: esantos@uu.net (Elaine Santos) Newsgroups: comp.dsp Subject: [FLAME] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jun15.015024.7249@uu.net> Date: Thu, 15 Jun 1995 01:50:24 GMT Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: Netscape 1.1N Lines: 10 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. 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? -- Elaine Santos Tape trading list upon request. SASE required for international mail. From bgirard@hanse.de Fri Jun 16 23:35:24 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!bgirard From: bgirard@hanse.de (Bastien Girard) Newsgroups: comp.dsp Subject: Re: [FLAME] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jun16.233524.1155@hanse.de> Date: Fri, 16 Jun 1995 23:35:24 GMT References: <1995Jun15.015024.7249@uu.net> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Jun15.015024.7249@uu.net>, esantos@uu.net (Elaine Santos) 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. -- Bastien Girard Tape trading list upon request. SASE required for international mail. From eweber@earthlink.net Sun Jun 18 22:43:24 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!eweber From: eweber@earthlink.net (Emi Weber) Newsgroups: comp.dsp Subject: Re: [FLAME] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jun18.224324.9035@earthlink.net> Date: Sun, 18 Jun 1995 22:43:24 GMT References: <1995Jun15.015024.7249@uu.net> <1995Jun16.233524.1155@hanse.de> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jun16.233524.1155@hanse.de>, bgirard@hanse.de (Bastien Girard) 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. -- Emi Weber Hayes Optima 288 @ 9600 Telebit bps "Hardware is temporary. The signal survives." From pkuznetsov@kiae.su Tue Jun 20 07:14:24 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!kiae!pkuznetsov From: pkuznetsov@kiae.su (Pavel Kuznetsov) Newsgroups: comp.dsp Subject: Re: [FLAME] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jun20.071424.6073@kiae.su> Date: Tue, 20 Jun 1995 07:14:24 GMT References: <1995Jun15.015024.7249@uu.net> <1995Jun16.233524.1155@hanse.de> <1995Jun18.224324.9035@earthlink.net> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Jun18.224324.9035@earthlink.net>, eweber@earthlink.net (Emi Weber) 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. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Pavel Kuznetsov Practical Peripherals 14.4 @ 14,400 bps "Hardware is temporary. The signal survives."