COMPUTER SCIENCE AND ENGINEERING
COMPUTER ARCHITECTURE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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PC is incremented
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The Instruction at the MAR address is read from RAM
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The PC value is copied to the MAR
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The instruction in the MDR is decoded by the CU
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The value in the MDR is written to the address in the MAR.
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Detailed explanation-1: -Eventually, the instruction in the MDR is copied into the current instruction register (CIR) which acts as a temporary holding ground for the instruction that has just been fetched from memory. During the decode stage, the control unit (CU) will decode the instruction in the CIR.
Detailed explanation-2: -Decode stage The decoding process allows the CPU to determine what instruction is to be performed so that the CPU can tell how many operands it needs to fetch in order to perform the instruction. The opcode fetched from the memory is decoded for the next steps and moved to the appropriate registers.
Detailed explanation-3: -The instruction or data held in that memory address is sent along the data bus to the memory data register (MDR). The instruction or data held in the MDR is copied into the current instruction register (CIR). The instruction or data held in the CIR is decoded and then executed .
Detailed explanation-4: -memory data register (MDR)-holds the contents found at the address held in the MAR, or data which is to be transferred to primary memory. current instruction register (CIR)-holds the instruction that is currently being decoded and executed.