From rkarlsson@utexas.edu Sat Mar 11 11:51:59 1995 Path: ashpoly!cascade!bigsur!utexas!rkarlsson From: rkarlsson@utexas.edu (Raj Karlsson) Newsgroups: comp.dsp Subject: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar11.115159.8532@utexas.edu> Date: Sat, 11 Mar 1995 11:51:59 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 11 Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample. Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm. -- === Raj Karlsson === Dept of Electrical Engineering, University of Texas at Austin "Do not worship the copy." From skuznetsov@titech.ac.jp Sun Mar 12 10:12:59 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!titech!skuznetsov From: skuznetsov@titech.ac.jp (Steve Kuznetsov) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar12.101259.7139@titech.ac.jp> Date: Sun, 12 Mar 1995 10:12:59 GMT References: <1995Mar11.115159.8532@utexas.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Mar11.115159.8532@utexas.edu>, rkarlsson@utexas.edu (Raj Karlsson) writes: > Optimizing the Stardust Costas loop demodulator for the Motorola DSP56001 chip. > This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Steve Kuznetsov Zyxel U-1496E @ 33,600 bps "Tape doesn't lie at 02:14. Ears do." From mpark@berkeley.edu Sun Mar 12 21:20:59 1995 Path: ashpoly!cascade!bigsur!berkeley!mpark From: mpark@berkeley.edu (Mei Park) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar12.212059.4861@berkeley.edu> Date: Sun, 12 Mar 1995 21:20:59 GMT References: <1995Mar11.115159.8532@utexas.edu> <1995Mar12.101259.7139@titech.ac.jp> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Mar12.101259.7139@titech.ac.jp>, skuznetsov@titech.ac.jp (Steve Kuznetsov) 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. -- Mei Park "We don't sign stars. We build them." Mac IIci / 68882 FPU / System 7.5.1 From spopov@berkeley.edu Tue Mar 14 20:44:59 1995 Path: ashpoly!cascade!mxgate!coyoacan!berkeley!spopov From: spopov@berkeley.edu (Sergei Popov) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar14.204459.6273@berkeley.edu> Date: Tue, 14 Mar 1995 20:44:59 GMT References: <1995Mar11.115159.8532@utexas.edu> <1995Mar12.101259.7139@titech.ac.jp> <1995Mar12.212059.4861@berkeley.edu> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Mar12.212059.4861@berkeley.edu>, mpark@berkeley.edu (Mei Park) 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. -- Sergei Popov Opinions expressed are solely my own and not those of UC Berkeley Department of EECS. ------------------------------------------------------------