Answered: Explain mapping the main control…

7th Edition

ISBN:9780133594140

Author:James Kurose, Keith Ross

Publisher:James Kurose, Keith Ross

Chapter1: Computer Networks And The Internet

Section: Chapter Questions

Problem R1RQ: What is the difference between a host and an end system? List several different types of end...

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Explain mapping the main control function to gates.

Expert Solution

Step 1: Mapping the main control function to gates

The most common way to develop a control function is a structure called Programmable Logic Array (PLA).
The control function is very easy as it is not large and difficult.
Therefore, it is reasonable to implement the main control function with a group of gates which are unstructured.
The PLA contains an array of programmable AND gates that connect to an array of programmable OR gates.
The inputs of programmable AND gates are the inputs of function and their inverses.
The output of programmable AND gates is the inputs of programmable OR gates.
The number of logic gates might be larger and each logic gate could contain more inputs, when there are most of “64” possible opcodes and more control lines were used.
Another way to develop a logic function is using a structured 2-level logic array as any function can be calculated in “2” levels of logic.