Of the following, which best characterizes computers that use memory-mapped I/O?
2018
Of the following, which best characterizes computers that use memory-mapped I/O?
- A.
The computer provides special instructions for manipulating I/O ports
- B.
I/O ports are placed at addresses on the bus and are accessed just like other memory locations
- C.
To perform I/O operations, it is sufficient to place the data in an address register and call channel to perform the operation
- D.
I/O can be performed only when memory management hardware is turned on
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Correct answer: B
Memory-mapped I/O maps device registers into the main memory address space, allowing standard load and store instructions to access hardware. This architecture eliminates the need for special I/O instructions found in port-mapped systems.