Microprocessor Input/Output Architecture

There are at least as many different microprocessor input/output organizations, circuit configurations, and device types as there are microprocessor families and manufacturers. Due to the diversity of competing approaches and devices, their similarities and differences are not always evident. The fact that each manufacturer describes his approaches and devices differently, and the relative scarcity of formal text material on microprocessors, do not make the situation any better. In this short space there is no hope of comprehensively surveying all available approaches and devices (nor would I want to, even if space were available!). On the other hand, I can present an overview of basic microprocessor I/O organization and typical circuit configurations and devices. Using these concepts as a basis, one may be able to make comparisons between current and future approaches available commercially.