利用基本RS触发器实现双CPU系统共享硬件资源

阐述了巧妙地利用基本RS触发器输入信号由违反约束条件变化成符合约束条件的瞬间，触发器的两个输出立即会变化成稳定的互斥状态的特点，可开发出多个输入信号竞争时只有一个有效状态输出的逻辑电路；并以双CPU系统共享随机存储器原理为例，介绍利用基本RS触发器解决双方访问硬件时的冲突问题，对其中的核心硬件电路工作原理进行了剖析。

Hardware Resource Sharing by Two CPU Systems Utilizing a Fundamental RS Trigger

Fundamental RS trigger is a basic cell consisting of various triggers, but it has a restrction on its input signals. When the restriction is violeted, its outputs will be uncertain. Therefore, the restriction should be obeyed generally. But further analysis shows that the two outputs will change to two steady opposed states immediately at the very moment when the inputs restriction is changed from violeted to obeyed. If this character is used ingenious, a logical circuit with only one valid output state when several input signals competing can be developed. In this paper, based on the example of two CPU sharing one random memory, how to solve the conflict problem when the two CPU access the same hardware is introduced, and the principle of core circuit is also analyzed.