From llarsson@rwth-aachen.de Thu Mar 23 23:41:57 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!rwth-aachen!llarsson From: llarsson@rwth-aachen.de (Lars Larsson) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar23.234157.3672@rwth-aachen.de> Date: Thu, 23 Mar 1995 23:41:57 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: Netscape 1.1N 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. However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip? -- === Lars Larsson === Dept of Electrical Engineering, RWTH Aachen Informatik "Measuring a record you own is listening, not piracy." From cbrennan@mindspring.com Fri Mar 24 03:27:57 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!mindspring!cbrennan From: cbrennan@mindspring.com (Callum Brennan) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar24.032757.7567@mindspring.com> Date: Fri, 24 Mar 1995 03:27:57 GMT References: <1995Mar23.234157.3672@rwth-aachen.de> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Mar23.234157.3672@rwth-aachen.de>, llarsson@rwth-aachen.de (Lars Larsson) 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. -- Callum Brennan | cbrennan@mindspring.com PGP Key fingerprint: C093 755D 9BFE 5ABD "Keep the channels open." From bpopov@panix.com Sun Mar 26 02:27:57 1995 Path: ashpoly!cascade!brgate!saturno!panix!bpopov From: bpopov@panix.com (Bill Popov) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar26.022757.4582@panix.com> Date: Sun, 26 Mar 1995 02:27:57 GMT References: <1995Mar23.234157.3672@rwth-aachen.de> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Mar23.234157.3672@rwth-aachen.de>, llarsson@rwth-aachen.de (Lars Larsson) 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Bill Popov "Hold for relay." Amiga 3000T / TOS 4.04 From nmuller@kiae.su Mon Mar 27 11:25:57 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!kiae!nmuller From: nmuller@kiae.su (Natalia Müller) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar27.112557.3930@kiae.su> Date: Mon, 27 Mar 1995 11:25:57 GMT References: <1995Mar23.234157.3672@rwth-aachen.de> <1995Mar26.022757.4582@panix.com> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Mar26.022757.4582@panix.com>, bpopov@panix.com (Bill Popov) writes: > Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Natalia Müller Opinions expressed are solely my own and not those of Kurchatov Institute of Atomic Energy, Moscow. ------------------------------------------------------------ From anovak@netcom.com Wed Mar 29 00:17:57 1995 Path: ashpoly!cascade!transat!ukc!fennimore!netcom!anovak From: anovak@netcom.com (Aiko Novak) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar29.001757.9172@netcom.com> Date: Wed, 29 Mar 1995 00:17:57 GMT References: <1995Mar23.234157.3672@rwth-aachen.de> <1995Mar26.022757.4582@panix.com> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Mar26.022757.4582@panix.com>, bpopov@panix.com (Bill Popov) writes: > Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Aiko Novak "Row 14. No joke." 486DX4/100 (FreeBSD 2.0.5) / System 7.5.1