Assitance needed with Excercise 7.22 only please

Excercise 7.22 What is the CPI of the redesigned multicycle ARM processor fromExercise 7.20?

Excercise 7.20 Goliath Corp claims to have a patent on a three-ported register file. Rather than fighting Goliath in court, Ben Bitdiddle designs a new register file that has only a single read/write port (like the combined instruction and data memory). Redesign the ARM multicycle datapath and controller to use his new register file. ? Use the instruction mix from Example 7.5.

Example 7.5 The SPECINT2000 benchmark consists of approximately 25% loads, 10% stores, 13% branches, and 52% data-processing instructions.2 Determine the average CPI for this benchmark.

Solution: The average CPI is the sum over each instruction of the CPI for that instruction multiplied by the fraction of the time that instruction is used. For this benchmark, average CPI=(0.13)(3)+(0.52+0.10)(4)+(0.25)(5)=4.12. This is better than the worst-case CPI of 5, which would be required if all instructions took the same time.