From lkowalski@berkeley.edu Sat Jul 09 03:54:23 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!berkeley!lkowalski From: lkowalski@berkeley.edu (Lisa Kowalski) Newsgroups: comp.dsp Subject: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul09.035423.8337@berkeley.edu> Date: Sat, 09 Jul 1994 03:54:23 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: NewsWatcher 2.0b24 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. Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm. -- Lisa Kowalski | lkowalski@berkeley.edu PGP Key fingerprint: 865F 3DD7 AA14 B30B "Keep the channels open." From mkuznetsov@unam.mx Sat Jul 09 17:50:23 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!unam!mkuznetsov From: mkuznetsov@unam.mx (Mike Kuznetsov) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul09.175023.8847@unam.mx> Date: Sat, 09 Jul 1994 17:50:23 GMT References: <1994Jul09.035423.8337@berkeley.edu> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Jul09.035423.8337@berkeley.edu>, lkowalski@berkeley.edu (Lisa Kowalski) 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. -- Mike Kuznetsov "The carrier frequency does not drift by accident." 486DX2/66 (Linux 1.2.13) / AmigaOS 3.1 From slindqvist@purdue.edu Sun Jul 10 05:57:23 1994 Path: ashpoly!cascade!mxgate!coyoacan!purdue!slindqvist From: slindqvist@purdue.edu (Steve Lindqvist) Newsgroups: comp.dsp Subject: Re: Observation: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Jul10.055723.1211@purdue.edu> Date: Sun, 10 Jul 1994 05:57:23 GMT References: <1994Jul09.035423.8337@berkeley.edu> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1994Jul09.035423.8337@berkeley.edu>, lkowalski@berkeley.edu (Lisa Kowalski) 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. -- Steve Lindqvist -- Purdue University Engineering Computer Network "The carrier frequency does not drift by accident."