INTRODUCTION TO MICROPEOCESSOR
MICROPROCESSOR BASICS
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the memory chip is given preference
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IO chip is given preference
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CPU is given preference
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none
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Detailed explanation-1: -Memory-mapped I/O uses the same address space to address both main memory and I/O devices. The memory and registers of the I/O devices are mapped to (associated with) address values. So a memory address may refer to either a portion of physical RAM, or instead to memory and registers of the I/O device.
Detailed explanation-2: -Memory mapped I/O is an interfacing technique in which memory related instructions are used for data transfer and the device is identified by a 16-bit address. In this type, the I/O devices are treated as memory locations. The control signals used are MEMR and MEMW.
Detailed explanation-3: -The key factor of differentiation between memory-mapped I/O and Isolated I/O is that in memory-mapped I/O, the same address space is used for both memory and I/O device. While in I/O-mapped I/O, separate address spaces are used for memory and I/O device.
Detailed explanation-4: -I/O mapped I/Os have a separate address space from the memory. So, total addressed capacity is the number of I/Os connected and a memory connected. Separate I/O-related instructions are used to access I/Os. A separate signal is used for addressing an I/O device.