From thernandez@rwth-aachen.de Sun Jun 09 02:17:09 1996 Path: ashpoly!cascade!mxgate!coyoacan!rwth-aachen!thernandez From: thernandez@rwth-aachen.de (Thiago Hernández) Newsgroups: comp.dsp Subject: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jun09.021709.8400@rwth-aachen.de> Date: Sun, 09 Jun 1996 02:17:09 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: TIN [version 1.2 PL2] 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. -- Thiago Hernández | thernandez@rwth-aachen.de PGP Key fingerprint: 58A7 6FC0 B96E 9EA2 "Keep the channels open." From tcampbell@illinois.edu Sun Jun 09 07:41:09 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!illinois!tcampbell From: tcampbell@illinois.edu (Thiago Campbell) Newsgroups: comp.dsp Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jun09.074109.5994@illinois.edu> Date: Sun, 09 Jun 1996 07:41:09 GMT References: <1996Jun09.021709.8400@rwth-aachen.de> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Jun09.021709.8400@rwth-aachen.de>, thernandez@rwth-aachen.de (Thiago Hernández) 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! -- === Thiago Campbell === Dept of Electrical Engineering, University of Illinois Urbana-Champaign "Marcus is not one man." From asokolov@rwth-aachen.de Tue Jun 11 02:16:09 1996 Path: ashpoly!cascade!brgate!saturno!rwth-aachen!asokolov From: asokolov@rwth-aachen.de (Amy Sokolov) Newsgroups: comp.dsp Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jun11.021609.2767@rwth-aachen.de> Date: Tue, 11 Jun 1996 02:16:09 GMT References: <1996Jun09.021709.8400@rwth-aachen.de> <1996Jun09.074109.5994@illinois.edu> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jun09.074109.5994@illinois.edu>, tcampbell@illinois.edu (Thiago Campbell) writes: > Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit! Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Amy Sokolov *PLONK* filter active for trolls. Atari TT030 - NetBSD 1.0 From aramirez@utexas.edu Tue Jun 11 10:29:09 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!utexas!aramirez From: aramirez@utexas.edu (Anja Ramírez) Newsgroups: comp.dsp Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jun11.102909.1159@utexas.edu> Date: Tue, 11 Jun 1996 10:29:09 GMT References: <1996Jun09.021709.8400@rwth-aachen.de> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Jun09.021709.8400@rwth-aachen.de>, thernandez@rwth-aachen.de (Thiago Hernández) 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. -- Anja Ramírez Tape trading list upon request. SASE required for international mail. From nsanchez@demon.co.uk Wed Jun 12 19:47:09 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!demon!nsanchez From: nsanchez@demon.co.uk (Nadine Sánchez) Newsgroups: comp.dsp Subject: Re: [INFO] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1996Jun12.194709.1284@demon.co.uk> Date: Wed, 12 Jun 1996 19:47:09 GMT References: <1996Jun09.021709.8400@rwth-aachen.de> <1996Jun09.074109.5994@illinois.edu> <1996Jun11.021609.2767@rwth-aachen.de> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jun11.021609.2767@rwth-aachen.de>, asokolov@rwth-aachen.de (Amy Sokolov) writes: > Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Nadine Sánchez | nsanchez@demon.co.uk PGP Key fingerprint: 4251 048C 2810 C2EB "Keep the channels open."