Operating System Memory Protection in a Paged Environment
Memory protection in a paged environment is accomplished by protection bits associated with each frame. For example read-write, read-only or execute-only bit, and valid-invalid bit. Normally, these bits are kept in the page table. More ...
Analog to Digital Convertion with a Microcontroller
Analog-to-digital conversion (or A/D conversion), is an electronic process that converts a continuously variable signal into a digital signal (expressed as a string of 1s and 0s). More ...
How Computer Chips are Made
The oxygen is removed from silica by heating it with carbon. A tiny seed of silicon is then dipped into molten silicon. As the tiny crystal is slowly lifted out of the crucible silicon crystallizes around it. More ...
CPU Process Memory Address Binding
For a program to run on a CPU it must be brought from files in long-term, non-volatile storage to main memory. Addresses in the source program must be mapped to addresses in main memory. More ...
Data Structures - Linked List, Stack, Queue, and Tree
An array is a simple data structure in which each element can be accessed directly. But what about storing an item whose size may vary? And what about removing an item if the relative positions of the remaining items must be preserved? In such situations other data structures may be needed. More ...
Operating System Process Scheduling Queues
The objective of multiprogramming is to have some process running at all times, to maximize CPU utilization. To meet these objectives, the process scheduler selects a process from a queue for execution on the CPU. More ...
Logical Versus Physical Memory Addresses
Computers use logical and physical addresses to access memory locatiuons. The CPU generates logical addresses. At run-time the Memory Management Unit (MMU) maps logical addresses to physical addresses. More ...
Microcontroller Internal EEPROM (Electrically Erasable Programmable Read Only Memory) Memory
In some situations it is required that some program parameters such as configuration settings be keept after the system is powered off. This is made possible by including a EEPROM internally to the microcontroller. More ...
Computer Video Display
If you view a computer as an input-processing-output machine, you can use a keyboard or removable storage device as the input, a program as the processing, but what can you use to retrieve the output? One way to acquire the output, be it text or graphics, is with a video display. More ...
Binary Floating-Point Numbers
Floating-point numbers allow you to use the very large, and very small, numbers commonly found in scientific calculations. A binary floating-point number consists of three parts, the sign bit, the mantissa and the exponent. More ...
Basic Decoder Circuitry
A microprocessors is a circuit that reads and execute program instructions called opcodes. A decoder is a circuit that converts an opcode into signals tused to control the circuitry of the microprocessor to enable it to perform the instruction. More ...
Using the Microcontroller Timers
Timing is an essential function for generating signals with precisely determined duration, or for counting external events. For this reason, a timer subsystem is present in all microcontroller implementations. More ...
