Tag: Lookup Table

The “vocabulary” of instructions which any particular microprocessor chip possesses is specific to that model of chip. An Intel 80386, for example, uses a completely different set of binary codes than a Motorola 68020, for designating equivalent functions. Unfortunately, there are no standards in place for microprocessor instructions. This makes programming at the very lowest…

Early computer science pioneers such as Alan Turing and John Von Neumann postulated that for a computing device to be really useful, it not only had to be able to generate specific outputs as dictated by programmed instructions, but it also had to be able to write data to memory, and be able to act…

Feedback is a fascinating engineering principle. It can turn a rather simple device or process into something substantially more complex. We’ve seen the effects of feedback intentionally integrated into circuit designs with some rather astounding effects: Comparator + negative feedback—————-> controllable-gain amplifier Comparator + positive feedback—————-> comparator with hysteresis Combinational logic + positive feedback—> multivibrator…

Having learned about digital memory devices in the last chapter, we know that it is possible to store binary data within solid-state devices. Those storage “cells” within solid-state memory devices are easily addressed by driving the “address” lines of the device with the proper binary value(s). Suppose we had a ROM memory circuit written, or…

Suppose we wanted to build a device that could add two binary bits together. Such a device is known as a half-adder, and its gate circuit looks like this: The Σ symbol represents the “sum” output of the half-adder, the sum’s least significant bit (LSB). Cout represents the “carry” output of the half-adder, the sum’s…