Memory Structure and Function Overview

Memory Structure and Function

• Purpose of Memory:

  • Memory is a critical component that stores instructions waiting to be executed by the processor.

  • It also holds data needed by those instructions and the results obtained from processing the data.

• Categories of Stored Items:

  1. Operating System and System Software

  2. Application Programs

  3. Data Being Processed and Resulting Information

• Memory Addressing:

  • Each memory location has a unique address:

  • This address allows the processor to access the specific contents of that location.

  • It also facilitates the storage of new data into that location.

• Measurement Units of Memory:

  • Memory size is quantified in various units:

  • Kilobytes (KB or K)

  • Megabytes (MB)

  • Gigabytes (GB)

  • Terabytes (TB)

• Types of Memory:

  • The system unit features two principal types of memory:

  1. Volatile Memory

     • Characteristics:

       • Loses its contents when power is turned off.

     • Example: Random Access Memory (RAM)

  2. Nonvolatile Memory

     • Characteristics:

       • Retains contents even when power is lost.

     • Examples include:

       • Read Only Memory (ROM)

       • Flash Memory

       • CMOS

• Read-Only Memory (ROM):

  • Definition: Memory chips that store permanent data and instructions.

  • Primary Use:

  • Mostly utilized for storing firmware.

  • Special Type:

  • Programmable Read-Only Memory (PROM)