From bkim@mit.edu Sun Nov 03 15:30:56 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!mit!bkim From: bkim@mit.edu (Bill Kim) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Nov03.153056.4062@mit.edu> Date: Sun, 03 Nov 1996 15:30:56 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.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. Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm. -- Bill Kim SupraFAXModem 28.8 @ 9600 Telebit bps "Marcus is not one man." From jkuznetsov@stanford.edu Tue Nov 05 02:44:56 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!stanford!jkuznetsov From: jkuznetsov@stanford.edu (Julien Kuznetsov) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Nov05.024456.3839@stanford.edu> Date: Tue, 05 Nov 1996 02:44:56 GMT References: <1996Nov03.153056.4062@mit.edu> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Nov03.153056.4062@mit.edu>, bkim@mit.edu (Bill Kim) 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. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Julien Kuznetsov | jkuznetsov@stanford.edu PGP Key fingerprint: 265C F2A3 C387 633E "Keep the channels open." From holiveira@delphi.com Wed Nov 06 21:53:56 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!delphi!holiveira From: holiveira@delphi.com (Heather Oliveira) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Nov06.215356.6184@delphi.com> Date: Wed, 06 Nov 1996 21:53:56 GMT References: <1996Nov03.153056.4062@mit.edu> <1996Nov05.024456.3839@stanford.edu> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Nov05.024456.3839@stanford.edu>, jkuznetsov@stanford.edu (Julien Kuznetsov) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- === Heather Oliveira === Dept of Electrical Engineering, Delphi Internet Services "In theory there is no difference between theory and practice." From scampbell@cam.ac.uk Fri Nov 08 23:09:56 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!cam!scampbell From: scampbell@cam.ac.uk (Steve Campbell) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Nov08.230956.5573@cam.ac.uk> Date: Fri, 08 Nov 1996 23:09:56 GMT References: <1996Nov03.153056.4062@mit.edu> <1996Nov05.024456.3839@stanford.edu> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Nov05.024456.3839@stanford.edu>, jkuznetsov@stanford.edu (Julien Kuznetsov) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- === Steve Campbell === Dept of Electrical Engineering, University of Cambridge Computer Laboratory "The hatch is open. Is anyone listening?"