Question

If, in a single contiguous memory management system, the program is loaded at address 30215 , compute the physical addresses (in decimal) that correspond to the following logical addresses: a. 9223 b. 2302 c. 7044

Short answer

Physical addresses: a. 39438, b. 32517, c. 37259.

Step-by-step solution

Understanding Physical Address Calculation

To compute the physical address in a single contiguous memory management system, the formula used is: Physical Address = Base Address + Logical Address.

Step for Logical Address a: 9223

Use the given base address of 30215 and the logical address of 9223. The physical address is calculated as:\[30215 + 9223 = 39438\]Thus, the physical address for logical address 9223 is 39438.

Step for Logical Address b: 2302

Use the given base address of 30215 and the logical address of 2302.The physical address is calculated as:\[30215 + 2302 = 32517\]The physical address for logical address 2302 is 32517.

Step for Logical Address c: 7044

Use the given base address of 30215 and the logical address of 7044.The physical address is calculated as:\[30215 + 7044 = 37259\]The physical address for logical address 7044 is 37259.

Key concepts

Physical Address Computation

In memory management, understanding how to compute a physical address is crucial. Physical addresses determine the actual location in memory where data is stored. In a single contiguous memory system, calculating a physical address is straightforward. It involves adding a logical address (the relative address given by a program) to a base address (the starting point of a program in physical memory).

To break it down:

• **Base Address**: This is the starting address in memory where the application begins. It is unique for each program loaded into memory.
• **Logical Address**: This is an offset within the program. It is relative to the base address and is used by the program to manage data.
• **Physical Address**: This is the sum of the base address and the logical address. It signifies the exact location in physical memory.

Using the formula: ewline\[\text{Physical Address} = \text{Base Address} + \text{Logical Address}\]For example, if a program is loaded at a base address of 30215 and a logical address is 9223, the physical address would be computed by adding these two: \[30215 + 9223 = 39438\]Hence, the physical address is 39438.

Single Contiguous Memory System

The single contiguous memory system is a memory management approach where each process occupies a single continuous block of memory. This method allows each program to run with its memory space, making it easier to predict and manage memory usage.

Here are the key aspects:

• **Simplicity**: Because each process occupies a single block of memory, it’s a straightforward way of managing memory. This simplicity also reduces overhead for maintaining metadata about fragments, making it efficient.
• **Fixed Allocation**: Once a program's memory allocation is done, the program operates within a fixed space. This means if a program needs more space, it must wait until it can be allocated anew with enough memory.
• **Fragmentation**: Internal fragmentation can occur due to the fixed size of allocation blocks, resulting in unused memory within an allocated block.

This system works well when there are predictable memory needs, but it can be inefficient for systems with variable memory requirements.

Logical Address Conversion

Logical address conversion is essential for translating how programs reference memory into actual physical locations. A logical address is an abstract way for programs to manage memory without needing to understand complex hardware details.

Here is why logical address conversion is important:

• **Abstraction**: It allows programs to be written in a hardware-agnostic way. Programs use logical addresses to manage data, which is then converted to a physical address by the system.
• **Memory Protection**: This conversion protects different programs from interfering with each other by ensuring they operate within their unique address spaces.
• **Ease of Programming**: By removing the need to use specific physical addresses, programmers can focus on writing logic without worrying about memory layout.
  This conversion process is managed by the operating system using mechanisms such as the Memory Management Unit (MMU), ensuring that each logical address is properly translated into a usable physical address.