From mokonkwo@kiae.su Wed Oct 23 14:35:15 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!kiae!mokonkwo From: mokonkwo@kiae.su (Mikhail Okonkwo) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Oct23.143515.3030@kiae.su> Date: Wed, 23 Oct 1996 14:35:15 GMT Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm. -- Mikhail Okonkwo Opinions expressed are solely my own and not those of Kurchatov Institute of Atomic Energy, Moscow. ------------------------------------------------------------ From tkang@kiae.su Thu Oct 24 18:55:15 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!kiae!tkang From: tkang@kiae.su (Tyler Kang) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Oct24.185515.6423@kiae.su> Date: Thu, 24 Oct 1996 18:55:15 GMT References: <1996Oct23.143515.3030@kiae.su> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Oct23.143515.3030@kiae.su>, mokonkwo@kiae.su (Mikhail Okonkwo) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Tyler Kang Zyxel U-1496E @ 14,400 bps "A soul is not exclusive to biology." From ajohansson@delphi.com Sat Oct 26 18:26:15 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!delphi!ajohansson From: ajohansson@delphi.com (Andrei Johansson) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Oct26.182615.7436@delphi.com> Date: Sat, 26 Oct 1996 18:26:15 GMT References: <1996Oct23.143515.3030@kiae.su> <1996Oct24.185515.6423@kiae.su> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Oct24.185515.6423@kiae.su>, tkang@kiae.su (Tyler Kang) 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. -- Andrei Johansson Opinions expressed are solely my own and not those of Delphi Internet Services. ------------------------------------------------------------