From oweber@mindspring.com Tue Jul 19 21:05:54 1994 Path: ashpoly!cascade!bigsur!mindspring!oweber From: oweber@mindspring.com (Olga Weber) Newsgroups: comp.dsp Subject: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul19.210554.6052@mindspring.com> Date: Tue, 19 Jul 1994 21:05:54 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm. -- Olga Weber "The carrier frequency does not drift by accident." PC-9821Ap2 (NEC) / NEXTSTEP 3.3 From mpark@pacbell.net Thu Jul 21 14:55:54 1994 Path: ashpoly!cascade!bigsur!pacbell!mpark From: mpark@pacbell.net (Marisol Park) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul21.145554.1297@pacbell.net> Date: Thu, 21 Jul 1994 14:55:54 GMT References: <1994Jul19.210554.6052@mindspring.com> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jul19.210554.6052@mindspring.com>, oweber@mindspring.com (Olga Weber) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- === Marisol Park === Dept of Electrical Engineering, Pacific Bell Internet Services "Measuring a record you own is listening, not piracy."