List of interview questions on embedded processor [Part-II]. This post is continuation of previous post and very specific to the topic of microcontroller and assembler. I believe this post will be helpful to prepare for an interview of entry level position/fresher.
What is nibble, byte and word?
Nibble: In computing a nibble is a four bit aggregation or half an octet. As a nibble contain 4-bits. Byte: The byte is a unit of digital information in computing and telecommunications. The size of byte is typically hardware dependent but the modern de facto standard is 8-bits, as this is a convenient power of 2. Word: In computing and common processors used in personal computer for example Intel Pentiums and AMD Athalon, their IA-32 architecture is an extension of original Intel 8086 design which had a word size of 16-bit’s.
What is Interrupt?
Interrupt is a signal which breaks usual flow of a program to perform particular task and then come back to its usual flow of program.
What is Software Interrupt?
The software interrupt are program instructions. These instructions are inserted at desired locations in a program. While running a program, if software interrupt instruction is encountered then the processor executes an interrupt service routine.
What Is Hardware Interrupt?
If an interrupt is initiated in a processor by an appropriate signal at the interrupt pin, then the interrupt is called “hardware interrupt”.
What is Bus?
Bus is group of conducting lines that carries data address and control signal.
Why data bus is bi-directional?
The Microprocessor has to fetch (read) the data from memory or input device for processing and after processing, it has to store (write) the data to memory or output device hence the data bus is bi-directional.
What is meant by latch?
Latch is D-type flip-flop used as a temporary storage device controlled by timing signal, which can store 0 or 1. The primary function of a latch is data storage. It is used in output devices such as LED to hold the data for display.
What is stack?
Stack is a portion of RAM used for saving the content of program counter and general purpose register. And characterized by two fundamental operations: PUSH & POP
What is difference between RAM & ROM?
- RAM: Read/Write memory with high speed, volatile memory
- ROM: Read only memory with low speed, non-volatile memory
Can ROM be used as a stack?
ROM can’t be used as a stack because it’s not possible to write to the ROM.
Difference between Static RAM and Dynamic RAM?
- Static RAM: No Refreshing, 6 to 8 MOS transistors are required to form one memory cell, information stored as voltage level in flip-flop.
- Dynamic RAM: Refreshed periodically, 3 to 4 transistors are required to form one memory cell, information is stored as charge in the gate to substrate capacitance.