From anovak@tum.de Sat Feb 11 05:49:36 1995 Path: ashpoly!cascade!mxgate!coyoacan!tum!anovak From: anovak@tum.de (Aiko Novak) Newsgroups: comp.dsp Subject: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb11.054936.9305@tum.de> Date: Sat, 11 Feb 1995 05:49:36 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de 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. 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? -- Aiko Novak | anovak@tum.de PGP Key fingerprint: 8D0D 983A B388 7A1A "Keep the channels open." From mpopov@pipeline.com Sat Feb 11 16:48:36 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!pipeline!mpopov From: mpopov@pipeline.com (Marisol Popov) Newsgroups: comp.dsp Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb11.164836.1069@pipeline.com> Date: Sat, 11 Feb 1995 16:48:36 GMT References: <1995Feb11.054936.9305@tum.de> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Feb11.054936.9305@tum.de>, anovak@tum.de (Aiko Novak) 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. -- Marisol Popov Tape trading list upon request. SASE required for international mail. From dvasiliev@kth.se Mon Feb 13 01:16:36 1995 Path: ashpoly!cascade!bigsur!kth!dvasiliev From: dvasiliev@kth.se (Dmitri Vasiliev) Newsgroups: comp.dsp Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb13.011636.7073@kth.se> Date: Mon, 13 Feb 1995 01:16:36 GMT References: <1995Feb11.054936.9305@tum.de> <1995Feb11.164836.1069@pipeline.com> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Feb11.164836.1069@pipeline.com>, mpopov@pipeline.com (Marisol 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Dmitri Vasiliev US Robotics Courier V.34 @ 19,200 bps "The carrier frequency does not drift by accident." From ahughes@mit.edu Mon Feb 13 03:32:36 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!mit!ahughes From: ahughes@mit.edu (Amy Hughes) Newsgroups: comp.dsp Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Feb13.033236.9255@mit.edu> Date: Mon, 13 Feb 1995 03:32:36 GMT References: <1995Feb11.054936.9305@tum.de> <1995Feb11.164836.1069@pipeline.com> <1995Feb13.011636.7073@kth.se> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Feb13.011636.7073@kth.se>, dvasiliev@kth.se (Dmitri Vasiliev) writes: > Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit! Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Amy Hughes *PLONK* filter active for trolls. Commodore Amiga 500 (1MB OCS) - NetBSD 1.0