From jito@kth.se Wed Mar 06 08:08:28 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!kth!jito From: jito@kth.se (Ji-woo Ito) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Mar06.080828.2556@kth.se> Date: Wed, 06 Mar 1996 08:08:28 GMT Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip? -- Ji-woo Ito "Tape doesn't lie at 02:14. Ears do." PC-9821Ap2 (NEC) / Linux 1.2.13 From poliveira@mit.edu Thu Mar 07 09:36:28 1996 Path: ashpoly!cascade!transat!ukc!fennimore!mit!poliveira From: poliveira@mit.edu (Pavel Oliveira) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Mar07.093628.3327@mit.edu> Date: Thu, 07 Mar 1996 09:36:28 GMT References: <1996Mar06.080828.2556@kth.se> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1996Mar06.080828.2556@kth.se>, jito@kth.se (Ji-woo Ito) 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. Top-posters will be placed in my ~/.killfile without notice. -- Pavel Oliveira | poliveira@mit.edu PGP Key fingerprint: 8F1E ABC0 21AC 35F2 "Keep the channels open."