Computer Science Unit 2: Microprocessors

Microprocessor Overview

• Microprocessor, or logic chip, serves as the core of the CPU, acting as the "Heart of Computer."
• It performs arithmetic and logic operations utilizing registers for data storage.
• Typical operations include addition, subtraction, and data fetching through structured instructions.

Intel 8086 Microprocessor

• The 8086 is a 16-bit processor, featuring a 16-bit ALU and both internal and external data buses.
• Its architecture incorporates 20-bit address lines, allowing access to 1 MB (2^20 locations) of memory.

Pipelining and Segmentation

• Utilizes two-stage pipelining:
  • Fetch stage retrieves up to 6 bytes of instructions into a queue.
  • Execute stage processes these instructions.
• Segmentation divides memory into four distinct segments.

Operating Modes

• Functions in two modes:
  • Minimum Mode: Operates with a single microprocessor.
  • Maximum Mode: Utilizes multiple processors.
• Implements a memory banking system, splitting data storage into two banks of 512 KB.

Interrupts and Arithmetic Operations

• Supports 256 vectored interrupts for efficient task handling.
• Extensive instruction set facilitates multiplication and division operations.

8086 Architecture Components

• Key components include:
  • Arithmetic Logic Unit (ALU)
  • Flag Register
  • General Registers
  • Instruction Stream Byte Queue
  • Segment Registers

Execution and Bus Interface Units

• The CPU structure divides into:
  • Bus Interface Unit (BIU): Manages data transfer and bus control.
  • Execution Unit (EU): Executes instructions and performs calculations.

Signal Descriptions

• BHE (Bus High Enable) determines data transfer byte order based on address lines.
• Non-maskable interrupt (NMI) signals are crucial for prioritizing interrupts.
• Other signals regulate timing (CLK), memory readiness (READY), and data flow direction (DT/R).

Modes Signal Functions

• Minimum Mode signals handle single processor operations, e.g., INTA for interrupt acknowledgment.
• Maximum Mode signals allow multiple processors, denoting operation statuses and machine cycles.

Physical Address Calculation

• Physical addresses calculated from segment registers (CS, ES, SS) combined with respective offsets.
• Examples provided for segment bases and effective addresses.

Assemblers, Linkers, and Loaders

• Assemblers convert assembly code into machine language.
• Linkers and loaders manage code integration and memory allocation during execution.

Procedures and Macros

• Procedures organize code into reusable blocks, while macros simplify writing repeating tasks.
• Highlighted differences between macro and procedure definitions emphasize efficiency in coding.

Directives in Assembly Language

• Pseudo-operations guide the assembler, including DB for bytes, DD for double words, and SEGMENT statements.
• Defined end of code segments ensures clarity in code structure.

Flag Manipulation and Control Instructions

• Instructions like CLC, CMC, and STC manage flag states, crucial for controlling flow and operations.
• Machine control instructions like WAIT and HLT regulate processor actions.

Shift, Rotate, and String Instructions

• Provides functional detail on data manipulation methods via shift and rotate operations.
• String instructions streamline processing of sequences of data for optimization.

Explore the fundamental concepts of microprocessors in this quiz based on Unit 2 of Computer Science. Learn about the functions of a microprocessor, its role as the central processing unit, and its characteristics. Test your knowledge on arithmetic and logic operations in computing.