From mmoreau@cern.ch Sun Apr 16 00:57:14 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cern!mmoreau From: mmoreau@cern.ch (Mikhail Moreau) Newsgroups: comp.dsp Subject: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Apr16.005714.8170@cern.ch> Date: Sun, 16 Apr 1995 00:57:14 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. 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. -- Mikhail Moreau Opinions expressed are solely my own and not those of European Laboratory for Particle Physics, Geneva. ------------------------------------------------------------ From akarlsson@berkeley.edu Sun Apr 16 16:07:14 1995 Path: ashpoly!cascade!bigsur!berkeley!akarlsson From: akarlsson@berkeley.edu (Anja Karlsson) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Apr16.160714.4660@berkeley.edu> Date: Sun, 16 Apr 1995 16:07:14 GMT References: <1995Apr16.005714.8170@cern.ch> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Apr16.005714.8170@cern.ch>, mmoreau@cern.ch (Mikhail Moreau) writes: > Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. > 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. -- === Anja Karlsson === Dept of Electrical Engineering, UC Berkeley Department of EECS "Tape doesn't lie at 02:14. Ears do." From rsouza@delphi.com Tue Apr 18 02:41:14 1995 Path: ashpoly!cascade!transat!ukc!fennimore!delphi!rsouza From: rsouza@delphi.com (Raj Souza) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Apr18.024114.2038@delphi.com> Date: Tue, 18 Apr 1995 02:41:14 GMT References: <1995Apr16.005714.8170@cern.ch> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Apr16.005714.8170@cern.ch>, mmoreau@cern.ch (Mikhail Moreau) writes: > Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. > The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Raj Souza "Row 14. No joke." Atari Falcon 030 / TOS 4.04 From rsato@titech.ac.jp Wed Apr 19 19:37:14 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!titech!rsato From: rsato@titech.ac.jp (Rodrigo Sato) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Apr19.193714.5646@titech.ac.jp> Date: Wed, 19 Apr 1995 19:37:14 GMT References: <1995Apr16.005714.8170@cern.ch> <1995Apr18.024114.2038@delphi.com> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Apr18.024114.2038@delphi.com>, rsouza@delphi.com (Raj Souza) writes: > Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Rodrigo Sato Tape trading list upon request. SASE required for international mail.