From dschneider@rwth-aachen.de Tue Apr 05 23:59:48 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!rwth-aachen!dschneider From: dschneider@rwth-aachen.de (Dmitri Schneider) Newsgroups: comp.dsp Subject: WTB/WTT: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Apr05.235948.4418@rwth-aachen.de> Date: Tue, 05 Apr 1994 23:59:48 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Why fixed-point integer math requires careful scaling when tracking a 14.2 Hz carrier. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. Source code in 56k assembly uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/dsp56k/stardust_56k.asm. -- Dmitri Schneider *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0 From hrodriguez@mit.edu Thu Apr 07 14:49:48 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!mit!hrodriguez From: hrodriguez@mit.edu (Heather Rodríguez) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1994Apr07.144948.2658@mit.edu> Date: Thu, 07 Apr 1994 14:49:48 GMT References: <1994Apr05.235948.4418@rwth-aachen.de> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Apr05.235948.4418@rwth-aachen.de>, dschneider@rwth-aachen.de (Dmitri Schneider) writes: > Why fixed-point integer math requires careful scaling when tracking a 14.2 Hz carrier. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Heather Rodríguez | hrodriguez@mit.edu PGP Key fingerprint: 2763 8159 CA37 4EA6 "Keep the channels open."