Memory Representation

Memory Representation

• Bits and Bytes:
• The basic unit of memory is a bit, which can store a single binary value (0 or 1).
• A group of 8 bits is called a byte, which is commonly used to represent characters, numbers, and other data types.
• Memory Addresses:
• Each memory location has a unique address that allows the processor to locate and retrieve data.
• Addresses are typically expressed in hexadecimal format (base 16)

Example:

Imagine a small memory with a capacity of 16 bytes:

The addresses would range from 0x00 to 0x0F (0 to 15 in decimal).

If a variable named "age" is stored at address 0x05, the CPU would use this address to read or write its value.

 

• Memory Types:
• Primary Memory (Main Memory):
• Directly accessible to the CPU.
• Volatile (loses data when power is turned off).
• Commonly used types include:
• RAM (Random Access Memory)
• ROM (Read-Only Memory)

Note: While ROM shares some characteristics with primary memory, such as direct CPU access and persistent data storage, its read-only nature distinguishes it from the dynamic role of RAM in managing running programs. Therefore, it's more accurate to consider ROM as a special type of non-volatile memory that occupies a unique space between primary and secondary storage.

• Secondary Memory (Auxiliary Storage):
• Non-volatile (retains data even without power).
• Used for long-term storage.
• Examples include:
• Hard disk drives (HDDs)
• Solid-state drives (SSDs)
• Optical drives (CDs, DVDs)
• Flash drives