Length: 686 pages. Audience: System software developers. Service Performed: Partial original manuscript and editing. Online Document: Our work on this 32-bit manual was the basis for later revisions by Intel described in the Intel Architecture Software Developer's Manual, Volume 1, Volume 2, and Volume 3. Also see the related Intel i486 Microprocessor Hardware Reference Manual.
Publication: · Book i486 microprocessor programmer's reference manual Osborne/ Mc Graw- Hill Berkeley, CA, USA ©1990 ISBN: Book Bibliometrics · Downloads (6 Weeks n/a · Downloads (12 Months n/a · Downloads (cumulative n/a · Citation Count: 22.
Philip J. Koopman, Jr Draft text for article published in: Embedded Systems Programming, 6(5 May 1993, pp. 26-34 ( For a nicely typeset and edited version, please refer to that published article.) Abstract While the cache memory designed into advanced processors can significantly speed up the average performance of many programs, it also causes performance varations that surprise system designers and cause problems during product integration and deployment. This paper gives a description of cache memory behavior for real-time embedded systems, using the example of real data collected from an 80486 CPU interrupt service routine. While vendor-supported tools for predicting and bounding worst-case CPU delays are still in their infancy, there are some coping strategies that will reduce problems while minimizing risk. Contents Introduction Predictability and Determinacy An Example Cache and the 80486 Quantifying Surprises Surprises also Lurk Elsewhere The Bottom Line References Introduction Thinking of using a hot new CPU for a real-time control application? Do you embed PC chip sets in your product, but need a speed boost? Well, before you design-in the latest and greatest high end CPU, I'd like you to consider whether your application can tolerate the unpredictabilities introduced by features such as caches found in the latest and greatest processors. I'm going to show you how, in certain circumstances, the very design features that can make CPUs blazingly fast also cause surprises. And in embedded systems, surprises are seldom good. In particular, I'll be talking about problems introduced by the cache memory found in the Intel 80486. Fortunately, once you know some of the major sources of problems, you can account for them and avoid most surprises while reaping the benefits of embedding a high-end PC chipset. While I'll only cover the 80x86 family, most of the.
Download Now