CPUs and architecture
In microcontrollers and similar devices, which scheme assigns peripheral registers to the same address space as memory and operates them with ordinary memory read/write instructions?
- AVirtual memory
- BMemory-mapped I/O
- CCache coherence
Show answer and explanation
Answer: B. Memory-mapped I/O
In memory-mapped I/O, control registers of peripherals such as timers and UARTs are assigned specific addresses and operated with the same read/write instructions as memory. Compared with schemes that provide dedicated I/O instructions (port-mapped I/O), it keeps the instruction set simple.
- A. Virtual memory maps virtual addresses to physical addresses.
- B. Correct. Peripherals are assigned to the memory space and operated through it.
- C. Cache coherence keeps the contents of multiple caches consistent.