Computer architecture basics — which item is NOT a core functional block? Select the option that does not belong to the standard functional blocks of a general-purpose computer system.

Introduction / Context:
Most introductory computer architecture models describe a few core functional blocks present in virtually all systems. Recognizing which components are fundamental and which are optional peripherals helps students understand minimal system requirements vs. application-specific extensions.

Given Data / Assumptions:

• Core blocks typically include CPU, memory, and I/O interfaces.
• Peripherals such as converters, sensors, and actuators are application-dependent.

Concept / Approach:
A general-purpose computer requires a processing unit to execute instructions, memory to store code/data, and I/O ports to communicate with the outside world. An analog-to-digital converter (ADC) is crucial in embedded and instrumentation systems but is not universally required in computers (e.g., servers and laptops often lack dedicated ADC hardware). Therefore, it is not part of the minimal canonical block diagram.

Step-by-Step Solution:

Verification / Alternative check:
Standard textbooks depict the von Neumann or Harvard model showing CPU, memory, and I/O as the primary blocks; ADCs appear only in embedded system examples when analog signals are present.

Why Other Options Are Wrong:

• CPU, memory, and I/O ports are essential to execute programs and communicate with devices.
• System interconnect (bus/NoC) is part of how these blocks communicate; while architectural, it is inherent to the system.

Common Pitfalls:

• Assuming all modern systems need ADCs; many purely digital systems do not interface with analog signals at all.

Final Answer:
Analog-to-digital converter