From jnakamura@earthlink.net Sun Sep 18 11:02:03 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!jnakamura From: jnakamura@earthlink.net (Joachim Nakamura) Newsgroups: comp.dsp Subject: WTB/WTT: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Sep18.110203.3126@earthlink.net> Date: Sun, 18 Sep 1994 11:02:03 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 11 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. 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. -- Joachim Nakamura Hayes Optima 288 @ 19,200 bps "When every node is whole, the channel opens." From tsmirnov@uu.net Tue Sep 20 05:38:03 1994 Path: ashpoly!cascade!brgate!saturno!uu!tsmirnov From: tsmirnov@uu.net (Tobias Smirnov) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Sep20.053803.3995@uu.net> Date: Tue, 20 Sep 1994 05:38:03 GMT References: <1994Sep18.110203.3126@earthlink.net> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Sep18.110203.3126@earthlink.net>, jnakamura@earthlink.net (Joachim Nakamura) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Tobias Smirnov Tape trading list upon request. SASE required for international mail.