Execution_Time

##### Calculating execution time of a binary/program
- Components:
	- Cycles per Instruction (CPI)
	- Instruction Count (IC)
	- Clock Rate [frequency] (F)
	- Clock Period (T)
##### General Formula:
```
E = IC*CPI*T

Or

E = IC*CPI/F
```
- if non-uniform cycles per instruction:
	- calculate average CPI 
```
CPI`= ((IC(n)/IC)*CPI(n))+((IC(n+1)/IC)*CPI(n+1))+((IC(n+2)/IC)*CPI(n+2))...
```
```
Execution Time = (IC(n)*CPI(n))+(IC(n)*CPI(n)...) / Frequency
```

IMPORTANT
- If given microseconds:
	- must perform calculation as frequency --> ``1/(#us * 10^6)``


---
> Example:
IC(1)=9 | CPI(1)=8
IC(2)=5 | CPI(2)=3
IC(3)=8 | CPI(3)=9
Clock period = 8us

1. Conversion from microseconds to megahertz:
```
8us --> 0.125Mhz --> 0.125 * 10^6 OR SIMPLY 1/8*10^6
```
2. Equation:
```
((9*8)+(5*3)+(8*9))/(0.125*10^(6)) = 1.272 * 10^-3
```
3. Conversion back to microseconds
```
1.272 * 10^-3 --> 1272 * 10^-6 --> 1272us
```
Binary execution time of 1272us