ACtE08 · Chapter 8Mock Test 01🏛️ Past Licensure QuestionID: e123d630
Which of the following statements is incorrect for a microprocessor system using I/O mapped I/O?
Which of the following statements is incorrect for a microprocessor system using I/O mapped I/O?
Multiple Choice Options
- A✓ Correct Option
I/O address space is greater
- B
I/O and memory spaces are distinct
- C
Memory space available is not reduced
- D
Not all data transfer instructions are available
Detailed Technical Solution & Explanation
In I/O mapped I/O (isolated I/O), the I/O address space is much smaller (typically 8-bit addressing, providing only 256 ports in 8085) compared to the 16-bit memory address space (64 KB). Therefore, the claim that 'I/O address space is greater' is completely incorrect.
Option Analysis:
•
Option A (I/O address space is greater): Correct as the false statement. I/O mapped space is restricted and smaller than memory space.
•
Option B (I/O and memory spaces are distinct): True statement (separated by control signals).
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Option C (Memory space available is not reduced): True statement (unlike memory-mapped I/O).
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Option D (Not all data transfer instructions are available): True statement (restricted strictly to IN and OUT instructions).
Reference: Mock Test 01NEC Licensure Syllabus