In microprocessor I/O design, what is the technique called in which each input/output device is assigned a unique address within the normal memory address space so that the CPU can access devices using standard memory read/write instructions?

Introduction / Context:
Processors communicate with peripherals either through a separate I/O address space or by treating peripheral registers as if they were memory locations. The latter approach is widely used in microcontrollers and many CPU architectures because it simplifies instruction sets and programming models.

Given Data / Assumptions:

• Each device register is reachable with a unique address.
• Standard load/store instructions are used to access devices.
• No special I/O opcodes are required.

Concept / Approach:
Memory-mapped I/O integrates device registers into the processor's memory space. Reading or writing a specific address triggers peripheral hardware rather than returning ordinary RAM contents. This enables uniform access semantics and allows compilers to treat device registers as volatile memory locations.

Step-by-Step Solution:
Define the approach: devices appear at fixed addresses within the memory map.CPU uses the same bus cycles and control signals used for RAM to reach device registers.Software uses ordinary load/store instructions to configure and read devices.Therefore, the technique is called memory-mapped I/O.

Verification / Alternative check:
Inspect any common microcontroller datasheet: peripheral registers are listed with absolute addresses, and code uses standard read/write with volatile qualifiers to access them.

Why Other Options Are Wrong:
Wired I/O and dedicated I/O are vague terms and not the standard name.

I/O mapping is generic wording; the precise term is memory-mapped I/O.

Port-isolated I/O refers to a separate I/O space, which is the alternate method, not this one.

Common Pitfalls:
Assuming all CPUs support only one method. Some architectures provide both isolated I/O and memory-mapped I/O; software must follow the platform convention.

Final Answer:
memory-mapped I/O