From rreyes@utexas.edu Fri Jan 13 21:03:41 1995 Path: ashpoly!cascade!bigsur!utexas!rreyes From: rreyes@utexas.edu (Rodrigo Reyes) Newsgroups: comp.dsp Subject: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jan13.210341.8723@utexas.edu> Date: Fri, 13 Jan 1995 21:03:41 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 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. By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample. Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip? -- Rodrigo Reyes *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From jnakamura@ox.ac.uk Sat Jan 14 02:06:41 1995 Path: ashpoly!cascade!bigsur!ox!jnakamura From: jnakamura@ox.ac.uk (Ji-woo Nakamura) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jan14.020641.6983@ox.ac.uk> Date: Sat, 14 Jan 1995 02:06:41 GMT References: <1995Jan13.210341.8723@utexas.edu> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jan13.210341.8723@utexas.edu>, rreyes@utexas.edu (Rodrigo Reyes) 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. -- Ji-woo Nakamura Practical Peripherals 14.4 @ 28,800 bps "When every node is whole, the channel opens." From jpark@kiae.su Sun Jan 15 17:27:41 1995 Path: ashpoly!cascade!mxgate!coyoacan!kiae!jpark From: jpark@kiae.su (Jen Park) Newsgroups: comp.dsp Subject: Re: Discussion: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jan15.172741.8265@kiae.su> Date: Sun, 15 Jan 1995 17:27:41 GMT References: <1995Jan13.210341.8723@utexas.edu> <1995Jan14.020641.6983@ox.ac.uk> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jan14.020641.6983@ox.ac.uk>, jnakamura@ox.ac.uk (Ji-woo Nakamura) writes: > Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Jen Park Practical Peripherals 14.4 @ 28,800 bps "They will send a copy in my place."