Question 1

Define Microprocessor.

Accepted Answer

A Microprocessor is a highly integrated silicon chip containing the absolute core arithmetic, logic, and control circuitry required to execute central processing unit (CPU) functions.

Question 2

What is a Register?

Accepted Answer

A Register is an ultra-fast, temporary silicon memory storage unit physically embedded directly within the microprocessor architecture.

Question 3

Define Instruction Set.

Accepted Answer

The Instruction Set is the absolute dictionary of all machine-code commands a specific microprocessor is physically hardwired to understand.

Question 4

What is Addressing Mode?

Accepted Answer

Addressing Mode mathematically dictates exactly how the microprocessor locates the physical memory address of an instruction's operand.

Question 5

Define Interrupt.

Accepted Answer

An Interrupt is a critical hardware or software signal that violently halts the microprocessor's current execution flow to handle an urgent external event.

Question 6

What is DMA?

Accepted Answer

DMA (Direct Memory Access) allows high-speed I/O devices to mathematically read/write directly to RAM, completely bypassing the CPU.

Question 7

Define Memory Mapped I/O.

Accepted Answer

Memory Mapped I/O physically assigns standard RAM addresses to external I/O devices, allowing the CPU to treat them as memory locations.

Question 8

What is an Assembly Language?

Accepted Answer

Assembly Language is a low-level programming language utilizing human-readable mnemonics that physically correspond one-to-one with binary machine code instructions.

Question 9

Define Bus.

Accepted Answer

A Bus is a physical collection of copper wires utilized to transmit binary data, addresses, and control signals across the motherboard.

Question 10

What is a Port?

Accepted Answer

A Port is a physical hardware interface on the motherboard through which the microprocessor communicates with external I/O devices.

Question 11

Explain the internal architecture of 8085 microprocessor.

Accepted Answer

A rigorous architectural breakdown of the Intel 8085 Microprocessor, detailing its 8-bit ALU, 16-bit address bus, and the specific functional roles of its internal hardware registers (Accumulator, B, C, D, E, H, L, PC, SP).

Question 12

Describe the different addressing modes of 8085.

Accepted Answer

A detailed exploration of the five Addressing Modes of the 8085 microprocessor (Immediate, Register, Direct, Indirect, Implied), explaining exactly how the CPU mathematically locates operands in physical memory.

Question 13

Explain the concept of Interrupts in 8085 microprocessor.

Accepted Answer

A comprehensive technical breakdown of the 8085 Interrupt system, analyzing the strict hardware hierarchy of TRAP, RST 7.5, RST 6.5, RST 5.5, and INTR, and their vectored memory addresses.

Question 14

Discuss the 8255 Programmable Peripheral Interface (PPI).

Accepted Answer

An architectural review of the Intel 8255 Programmable Peripheral Interface (PPI), detailing its three 8-bit I/O ports and the mathematical configuration of its Control Word Register for BSR and I/O modes.

Question 15

Explain the concept of DMA (Direct Memory Access).

Accepted Answer

A deep dive into Direct Memory Access (DMA), explaining how the DMA controller aggressively hijacks the system buses using HOLD and HLDA signals to execute massive data transfers without CPU latency.

Question 16

Describe the 8237 DMA controller.

Accepted Answer

An architectural review of the Intel 8237 DMA Controller, detailing its 4 independent channels, Base and Current registers, and the rigorous mathematical execution of Block, Single, and Demand transfer modes.

Question 17

Explain the interfacing of 8085 with memory.

Accepted Answer

A definitive explanation of Interfacing the 8085 with Memory, detailing the critical hardware mechanics of Address Decoding, absolute memory mapping utilizing NAND gates or 74LS138 decoders, and control signal generation.

Question 18

(a) Explain the Pin Diagram of 8085 in detail. (b) Describe the functional un…

Accepted Answer

An exhaustive architectural analysis of the Intel 8085 Microprocessor Pin Diagram and Functional Units, detailing the highly optimized multiplexed Address/Data bus, hardware interrupt vectors, and the internal ALU/Register execution pipeline.

Question 19

(a) Explain the instruction set of 8085 with classification (Data Transfer, A…

Accepted Answer

A definitive classification of the 8085 Instruction Set (Data Transfer, Arithmetic, Logical, Branch, Stack), followed by the mathematical engineering of a fully commented Assembly Language program to add two 8-bit hex numbers from memory.

Question 20

(a) Explain the timing diagrams of 8085 for Memory Read and Memory Write oper…

Accepted Answer

An advanced architectural breakdown of 8085 Timing Diagrams, mathematically analyzing the T-states of Memory Read and Write machine cycles, and exploring how Wait States solve catastrophic synchronization failures with slow RAM.

Question 21

(a) Explain the 8255 PPI in detail including its modes of operation. (b) Disc…

Accepted Answer

A definitive engineering analysis of the 8255 Programmable Peripheral Interface, mathematically detailing its Mode 0, Mode 1, and Mode 2 operational architectures, alongside the exact hardware address decoding required to interface it with the 8085 CPU.

Question 22

(a) Explain the 8086 microprocessor architecture in detail. (b) Discuss the d…

Accepted Answer

A catastrophic architectural evolution: An exhaustive breakdown of the Intel 8086 Microprocessor, detailing its dual-pipeline architecture (BIU and EU), 1-Megabyte memory segmentation, and a rigorous structural comparison proving its absolute dominance over the archaic 8085.

Microprocessor and Interfaces