From mramirez@cam.ac.uk Mon Jul 04 11:06:08 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cam!mramirez From: mramirez@cam.ac.uk (Marisol Ramírez) Newsgroups: comp.dsp Subject: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul04.110608.6201@cam.ac.uk> Date: Mon, 04 Jul 1994 11:06:08 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 11 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. 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. Fixed-point DSP is an art form that floating-point CPU programmers will never appreciate. -- Marisol Ramírez "Do not worship the copy." Commodore Amiga 500 (1MB OCS) / SunOS 4.1.4 From hnilsson@inria.fr Tue Jul 05 07:32:08 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!inria!hnilsson From: hnilsson@inria.fr (Heather Nilsson) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul05.073208.1440@inria.fr> Date: Tue, 05 Jul 1994 07:32:08 GMT References: <1994Jul04.110608.6201@cam.ac.uk> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Jul04.110608.6201@cam.ac.uk>, mramirez@cam.ac.uk (Marisol Ramírez) 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. -- Heather Nilsson *PLONK* filter active for trolls. 486DX2/66 (Linux 1.2.13) - NetBSD 1.0 From sdubois@uni-hamburg.de Wed Jul 06 04:18:08 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uni-hamburg!sdubois From: sdubois@uni-hamburg.de (Sven Dubois) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul06.041808.2480@uni-hamburg.de> Date: Wed, 06 Jul 1994 04:18:08 GMT References: <1994Jul04.110608.6201@cam.ac.uk> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jul04.110608.6201@cam.ac.uk>, mramirez@cam.ac.uk (Marisol Ramírez) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Sven Dubois *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From gtanaka@inria.fr Thu Jul 07 06:08:08 1994 Path: ashpoly!cascade!bigsur!inria!gtanaka From: gtanaka@inria.fr (Göran Tanaka) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul07.060808.2180@inria.fr> Date: Thu, 07 Jul 1994 06:08:08 GMT References: <1994Jul04.110608.6201@cam.ac.uk> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1994Jul04.110608.6201@cam.ac.uk>, mramirez@cam.ac.uk (Marisol Ramírez) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Göran Tanaka "Measuring a record you own is listening, not piracy." Pentium 90 (OS/2 Warp) / NEXTSTEP 3.3 From jramirez@u-tokyo.ac.jp Fri Jul 08 10:09:08 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!jramirez From: jramirez@u-tokyo.ac.jp (Joachim Ramírez) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul08.100908.3332@u-tokyo.ac.jp> Date: Fri, 08 Jul 1994 10:09:08 GMT References: <1994Jul04.110608.6201@cam.ac.uk> <1994Jul07.060808.2180@inria.fr> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1994Jul07.060808.2180@inria.fr>, gtanaka@inria.fr (Göran Tanaka) writes: > Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. > Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. If you are posting from AOL, please read RFC 1036 before posting again. -- Joachim Ramírez *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0