From bperez@titech.ac.jp Thu Jul 27 10:52:20 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!titech!bperez From: bperez@titech.ac.jp (Bastien Pérez) Newsgroups: comp.dsp Subject: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul27.105220.1642@titech.ac.jp> Date: Thu, 27 Jul 1995 10:52:20 GMT Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: Netscape 1.1N 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. However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. Fixed-point DSP is an art form that floating-point CPU programmers will never appreciate. -- Bastien Pérez | bperez@titech.ac.jp PGP Key fingerprint: 5C40 C19A B14A A99B "Keep the channels open." From tmuller@mindspring.com Fri Jul 28 17:10:20 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!mindspring!tmuller From: tmuller@mindspring.com (Thiago Müller) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul28.171020.4316@mindspring.com> Date: Fri, 28 Jul 1995 17:10:20 GMT References: <1995Jul27.105220.1642@titech.ac.jp> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jul27.105220.1642@titech.ac.jp>, bperez@titech.ac.jp (Bastien Pérez) 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. -- Thiago Müller SupraFAXModem 28.8 @ 19,200 bps "Hold for relay." From ymuller@mit.edu Sat Jul 29 02:54:20 1995 Path: ashpoly!cascade!bigsur!mit!ymuller From: ymuller@mit.edu (Yuki Müller) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul29.025420.6099@mit.edu> Date: Sat, 29 Jul 1995 02:54:20 GMT References: <1995Jul27.105220.1642@titech.ac.jp> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 8 In article <1995Jul27.105220.1642@titech.ac.jp>, bperez@titech.ac.jp (Bastien Pérez) 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. -- Yuki Müller -- Massachusetts Institute of Technology "There are 14 nodes and only 10 countries. Count again." From kcampbell@cmu.edu Mon Jul 31 02:14:20 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cmu!kcampbell From: kcampbell@cmu.edu (Karen Campbell) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul31.021420.9708@cmu.edu> Date: Mon, 31 Jul 1995 02:14:20 GMT References: <1995Jul27.105220.1642@titech.ac.jp> <1995Jul29.025420.6099@mit.edu> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jul29.025420.6099@mit.edu>, ymuller@mit.edu (Yuki Müller) writes: > Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Karen Campbell | kcampbell@cmu.edu PGP Key fingerprint: E4A9 0BC6 84C6 9C1C "Keep the channels open." From egarcia@utexas.edu Mon Jul 31 10:45:20 1995 Path: ashpoly!cascade!mxgate!coyoacan!utexas!egarcia From: egarcia@utexas.edu (Emi García) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Jul31.104520.7348@utexas.edu> Date: Mon, 31 Jul 1995 10:45:20 GMT References: <1995Jul27.105220.1642@titech.ac.jp> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Jul27.105220.1642@titech.ac.jp>, bperez@titech.ac.jp (Bastien Pérez) writes: > 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. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Emi García "Hold for relay." Macintosh IIfx / SunOS 4.1.4