From rrobertson@delphi.com Fri May 06 18:46:03 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!delphi!rrobertson From: rrobertson@delphi.com (Rodrigo Robertson) Newsgroups: comp.dsp Subject: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994May06.184603.6148@delphi.com> Date: Fri, 06 May 1994 18:46:03 GMT Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample. 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. -- Rodrigo Robertson Opinions expressed are solely my own and not those of Delphi Internet Services. ------------------------------------------------------------ From tkarlsson@titech.ac.jp Sat May 07 05:31:03 1994 Path: ashpoly!cascade!transat!ukc!fennimore!titech!tkarlsson From: tkarlsson@titech.ac.jp (Tobias Karlsson) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994May07.053103.4622@titech.ac.jp> Date: Sat, 07 May 1994 05:31:03 GMT References: <1994May06.184603.6148@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 <1994May06.184603.6148@delphi.com>, rrobertson@delphi.com (Rodrigo Robertson) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > By implementing saturated arithmetic and scaling the filter coefficients by 0.5, the loop runs in 18 instruction cycles per sample. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Tobias Karlsson Opinions expressed are solely my own and not those of Tokyo Institute of Technology Computer Centre. ------------------------------------------------------------ From smacdonald@cern.ch Sun May 08 03:29:03 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cern!smacdonald From: smacdonald@cern.ch (Steve MacDonald) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994May08.032903.8961@cern.ch> Date: Sun, 08 May 1994 03:29:03 GMT References: <1994May06.184603.6148@delphi.com> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994May06.184603.6148@delphi.com>, rrobertson@delphi.com (Rodrigo Robertson) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit! Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Steve MacDonald -- European Laboratory for Particle Physics, Geneva "Hold for relay." From goliveira@delphi.com Mon May 09 04:47:03 1994 Path: ashpoly!cascade!brgate!saturno!delphi!goliveira From: goliveira@delphi.com (Graham Oliveira) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994May09.044703.6200@delphi.com> Date: Mon, 09 May 1994 04:47:03 GMT References: <1994May06.184603.6148@delphi.com> <1994May08.032903.8961@cern.ch> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994May08.032903.8961@cern.ch>, smacdonald@cern.ch (Steve MacDonald) writes: > Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit! Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Graham Oliveira *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From rramirez@netcom.com Tue May 10 21:40:03 1994 Path: ashpoly!cascade!transat!ukc!fennimore!netcom!rramirez From: rramirez@netcom.com (Rodrigo Ramírez) Newsgroups: comp.dsp Subject: Re: Data: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994May10.214003.7071@netcom.com> Date: Tue, 10 May 1994 21:40:03 GMT References: <1994May06.184603.6148@delphi.com> <1994May08.032903.8961@cern.ch> <1994May09.044703.6200@delphi.com> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994May09.044703.6200@delphi.com>, goliveira@delphi.com (Graham Oliveira) 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. -- Rodrigo Ramírez "Marcus is not one man." Mac IIci / 68882 FPU / System 7.5.1