Microprocessors & Microcontrollers

8284 Clock Generator

8284 clock generator is an IC developed by Intel to provide clock frequency, ready and reset signal to the 8086/8088 microprocessor. It is an 18 pin chip. 8284 produces the clock signal, synchronizes it with the ready and reset signal and provides it to the microprocessor. Functions of 8284 It provides a stable clock to …

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Assembler Directives

Definition: Assembler directives are the instructions used by the assembler at the time of assembling a source program. More specifically, we can say, assembler directives are the commands or instructions that control the operation of the assembler. Assembler directives are the instructions provided to the assembler, not the processor as the processor has nothing to …

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Assembly Language Programming

Assembly language programming is a low-level programming language in which the instructions are written in the form of mnemonics. More simply, we can say the language in the form of mnemonics is known as assembly language. This programming language allows the creation of human-readable program equivalent to machine code. Now a question arises: What are …

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Semiconductor Memory

Definition: Semiconductor memory is the main memory element of a microcomputer-based system and is used to store program and data. The main memory elements are nothing but semiconductor devices that stores code and information permanently. The semiconductor memory is directly accessible by the microprocessor. And the access time of the data present in the primary …

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Instruction Set of 8086 Microprocessor

We know that instructions are the binary commands used for the execution of any operation. In the previous article, we have discussed the instruction set of the 8085 microprocessor. Here in this article, we will discuss the instruction set supported by the 8086 microprocessor. 8086 supports various instructions including those supported by 8085. However, 8086 …

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8251 USART

8251 USART is a universal synchronous and asynchronous controller designed by Intel basically to facilitate communication. USART stands for Universal Synchronous and Asynchronous Receiver Transmitter and functions as an intermediary that allows serial and parallel communication between the microprocessor and the peripheral devices. We know that microprocessors allow parallel communication. And in parallel communication, the …

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Interrupts in 8085 Microprocessor

Interrupts are the signals that are generally produced by the devices externally connected to the microprocessor, requesting for the services. Whenever an interrupt request is generated in the system then it must not be neglected and be acknowledged as soon as possible. Basically whenever an interrupt is generated then the microprocessor suspends its current execution …

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8259 Programmable Interrupt Controller

Programmable interrupt controllers are used to enhance the number of interrupts of a microprocessor. 8259 is a programmable interrupt controller which shows compatibility with 8085 microprocessor. It is also known as a priority interrupt controller and was designed by Intel to increase the interrupt handling ability of the microprocessor. An 8259 PIC never services an …

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8255 PPI

8255 is a programmable I/O device that acts as interface between peripheral devices and the microprocessor for parallel data transfer. 8255 PPI (programmable peripheral interface) is programmed in a way so as to have transfer of data in different conditions according to the need of the system. In 8255, 24 pins are assigned to the …

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80386 Microprocessor

80386 Microprocessor is a 32-bit processor that holds the ability to carry out 32-bit operation in one cycle. It has data and address bus of 32-bit each. Thus has the ability to address 4 GB (or 232) of physical memory. Multitasking and protection capability are the two key characteristics of 80386 microprocessor. 80386 has an …

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