Article View: sci.electronics
Article #11806Re: microcontrollers
From: Jim Cathey
Date: Thu, 12 Nov 1992 18:52
Date: Thu, 12 Nov 1992 18:52
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1633 bytes
In article <11NOV199219370593@rigel.tamu.edu> rahhelp@rigel.tamu.edu (Ronald A. Huizar) writes: >planning to use the MC68HC811E2 can only address about 64K of external >... >about 3 Meg of memeory. To much for the E2. So I know that the Ever heard of bank-switching? Your massive data needs can be easily handled this way, because you don't need simultaneous access to all that data. Your application is specific (and simple) enough that you can afford to call a subroutine to fetch each sample from RAM that's not directly in your address space. No problem. A similar technique was used in many external print spoolers, which had 8048's in them. These only can directly address something like 2K of memory (my memory's fading fast), but these used clever bit-banging techniques on DRAMs connected to I/O ports to store hundreds of K of data. Engineering Rule #3b: Work smart, not hard. -- +----------------+ ! II CCCCCC ! Jim Cathey ! II SSSSCC ! ISC-Bunker Ramo ! II CC ! TAF-C8; Spokane, WA 99220 ! IISSSS CC ! UUCP: uunet!isc-br!jimc (jimc@isc-br.isc-br.com) ! II CCCCCC ! (509) 927-5757 +----------------+ "PC's --- the junk bonds of the computer industry"
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Path: arc1-ca.pugleaf.net!sparky!uunet!gossip.pyramid.com!olivea!isc-br!tau-ceti!jimc From: jimc@tau-ceti.isc-br.com (Jim Cathey) Newsgroups: sci.electronics Subject: Re: microcontrollers Keywords: sizes? External Memory Capability Message-ID: <2820@tau-ceti.isc-br.com> Date: 12 Nov 92 18:52:15 GMT References: <11NOV199219370593@rigel.tamu.edu> Organization: ISC - Bunker Ramo, Spokane, WA Lines: 26