Instruction Class Count:
1: 9
2: 5
3: 9

If it is executed on a processor with a clock period of 8 microseconds, and the following Instruction Class CPIs, what is the execution time in microseconds? Round to the nearest 0.1 microseconds.

Instruction Class CPI:
1: 8
2: 3
3: 8

A. 64.0 μs
B. 65.5 μs
C. 66.9 μs
D. 68.3 μs

To find the execution time, multiply the instruction count of each class with its respective CPI, and then multiply by the clock period. Finally, sum up the results. Therefore, the correct answer is Option A. 64.0 μs.

Explanation:

To find the execution time, we multiply the instruction count of each class with its respective CPI, and then multiply by the clock period. Finally, we sum up the results.

For Instruction Class 1, the execution time is 9 * 8 = 72 microseconds.

For Instruction Class 2, the execution time is 5 * 3 = 15 microseconds.

For Instruction Class 3, the execution time is 9 * 8 = 72 microseconds.

Adding these together, the total execution time is 72 + 15 + 72 = 159 microseconds.

Rounding to the nearest 0.1 microseconds, the execution time is approximately 159.0 microseconds.