A processor has separate instruction and data caches, each requiring two cycles

Question

A processor has separate instruction and data caches, each requiring two cycles for any operation. It includes a single 2-cycles execution unit responsible for executing all ALU and LOAD instructions. As a result, the instruction pipeline has the following eight stages: IF1, IF2, ID, EX1, EX2, MEM1, MEM2, WB. In the absence of hazards the pipeline has a CPl of 1. The processor has no hardware support for dynamic scheduling. The instruction stream executed by the processor consists of 25% Load instructions and 40% ALU instructions. The frequencies of RAW data dependencies between these two instructions and the instructions following them are: Instruction i LOAD ALU RAW in instructioni+1 30% 20% RAW in instruction i + 2, but not in i + 1 12% 10% RAW in instruction i + 3, but neither in i+ 1 nor in i + 2 10% 5% RAW in instruction i +4, but not in an earlier one 5% 1% Calculate the contribution to the CPI of the processor due to RAW data hazards assuming that NO DATA FORWARDING IS SUPPORTED Note that the Register File can execute a write followed by a read in the same cycle. Contribution to CPI

Explanation / Answer

Here the contribution to cpi is only the 19%.

That 19% will help to execute and read in the same cycle.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.