The execution time of a program depends on the following:
| || IC: the instruction count i.e., the number of instructions
executed in the program
| || CPI: the number of clocks needed for execution per instruction
| || τ: the clock period
Thus, the execution time of a program, T, can be expressed as:
T = IC x CPI x τ
To reduce the execution time of a program, this can be achieved
through one of the following:
| || 1. Reduce the number of in the instructions in the program.
| || 2. Reduce the number of clocks required for executing each
| || 3. Reduce the clock period.
Reducing the number of instructions in a program is the task
of the programmer or compiler. Reducing the clock period can
be achieved mainly by using a fast implementation technology.
However, the number of clocks required for executing each instruction
can be reduced by using multiple-bus CPU organization.
Next, we will see two-bus and three-bus CPU organizations and
their impact on reducing the number of clocks required for