Microprocessor and Microcontroller Part-I

Q.  What is microprocessor?

Ans: It is a program controlled semi conductor device (IC), which fetches, decodes and execute instructions.

Q.  What are the basic units of microprocessor?

Ans: The basic units or building blocks of microprocessor are ALU, an array of registers and control unit.

Q.  What is a bus?

Ans: Bus is a group of conducting lines that carries data, address and control signals.  

Q.  Why data bus is bi-directional?

Ans: The microprocessor is 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 devices. Hence the data bus is bi-directional.

Q.  Why Address bus is bi-directional?

Ans: The address is an identification number used by the microprocessor to identify or access a memory location or input/ output device. It is an output signal from the processor. Hence the address bus is unidirectional.

Q.  Define machine cycle?

Ans: Machine cycle is defined as the time required to complete one operation of accessing memory input/output, or acknowledging an external request. This cycle may consists of three to six T-states.