CPU datapath behavior: In a stored-program computer, the arithmetic/logic unit (ALU) computes results that are then written to registers and, under control of the instruction, may be stored to memory. Assess the statement that “the ALU will send the results of its decisions to memory.”

Introduction / Context:
The CPU datapath consists of the ALU, register file, buses, and control logic. After performing arithmetic or logical operations, results are typically captured in registers. Depending on the instruction (e.g., store), data may then be written to memory.

Given Data / Assumptions:

• Stored-program model (von Neumann or Harvard variations).
• ALU outputs are available on an internal bus.
• Control unit orchestrates register writes and memory stores.

Concept / Approach:
The ALU itself does not permanently “hold” results; it produces outputs combinationally or at a pipeline stage. Results are clocked into architectural registers. When an instruction requires it (e.g., STR, ST, MOV to memory-mapped I/O), the data is driven onto the memory bus and written to an address.

Step-by-Step Solution:

Verification / Alternative check:
Instruction traces show ALU result flowing to registers, then a subsequent micro-operation or instruction performing a memory write.

Why Other Options Are Wrong:
“Incorrect” would deny standard CPU behavior. Architecture types (Harvard vs von Neumann) affect buses, not the fundamental flow that results can be stored to memory.

Common Pitfalls:
Assuming ALU writes memory directly without control; ignoring cache and write-buffer layers that sit between registers and main memory.

Final Answer:
Correct