Question 2.
The primary oscillator in Explorer 16 is used as the clock source and its frequency is 7.648 GHz. The PLL is used. In that case, what is Fcy (Internal instruction cycle frequency)? Also, what is Tcy? You must show your calculation. Failing to do so will result zero mark for this question.
To calculate Fcy, we need to determine the division factor used by the PLL. Let's assume the division factor is N.
The PLL input clock frequency (Fosc) is 7.648 GHz, and the PLL output clock frequency (Fcy) is what we want to find.
Using the following formula for the PLL division factor:
N = Fosc / Fcy
We can rearrange the equation to solve for Fcy:
Fcy = Fosc / N
Now, we need to determine the value of N.
The primary oscillator frequency (Fosc) is provided as 7.648 GHz. However, this frequency is too high for the PLL to handle directly. The PLL can handle frequencies up to 80 MHz.
So, we need to find the maximum possible division factor that will still result in a frequency within the acceptable range.
Let's assume the maximum division factor is M.
M = Fosc / 80 MHz
M = 7.648 GHz / 80 MHz
M = 95.6
Therefore, the maximum division factor (M) is 95.6.
Now, we need to find the highest possible value for the division factor N.
To achieve this, we use the equation:
N = Ceiling(M / 2)
where Ceiling(.) is the ceiling function, which rounds the result up to the nearest integer.
N = Ceiling(95.6 / 2)
N = Ceiling(47.8)
N = 48
So, the division factor for the PLL (N) is 48.
Now, we can calculate Fcy.
Fcy = Fosc / N
Fcy = 7.648 GHz / 48
Fcy = 159.33 MHz
Therefore, the internal instruction cycle frequency (Fcy) is 159.33 MHz.
To calculate Tcy, we use the equation:
Tcy = 1 / Fcy
Tcy = 1 / 159.33 MHz
Tcy ≈ 6.279 ns
Therefore, the internal instruction cycle time (Tcy) is approximately 6.279 nanoseconds.
To calculate the Internal Instruction Cycle Frequency (Fcy) and the Instruction Cycle Time (Tcy), we need to know the multiplication factor (M) of the Phase-Locked Loop (PLL) used in the system.
Assuming the PLL has a multiplication factor of M, we can calculate Fcy using the formula:
Fcy = (Primary Oscillator Frequency / M) / 4
In this case, the primary oscillator frequency is given as 7.648 GHz.
To find the multiplication factor (M) of the PLL, we can use the formula:
M = PLL Output Frequency / Primary Oscillator Frequency
Since the PLL output frequency is not provided, we cannot calculate the exact values of Fcy and Tcy without this information.
Please provide the output frequency of the PLL for a more accurate calculation.
To find the value for Fcy (Internal instruction cycle frequency) and Tcy (Instruction cycle time), we need to use the formula:
Fcy = Fosc / PLLDIV
Where:
- Fcy is the internal instruction cycle frequency
- Fosc is the oscillator frequency
- PLLDIV is the PLL divisor
In this case, the oscillator frequency (Fosc) is given as 7.648 GHz, and it is mentioned that the PLL is used. However, the value for the PLLDIV is not provided in the question.
To determine the value of PLLDIV, we need additional information or assumptions about the system configuration. Without this information, it is not possible to calculate the exact values for Fcy and Tcy.
Assuming that the PLLDIV is set to 1 (no division), we can calculate the values as follows:
Fcy = 7.648 GHz / 1 = 7.648 GHz
Tcy = 1 / Fcy = 1 / 7.648 GHz
Since the frequency given is in gigahertz (GHz), we need to convert it to hertz (Hz). The conversion from GHz to Hz is:
1 GHz = 1,000,000,000 Hz.
Therefore:
Tcy = 1 / (7.648 GHz) = 1 / (7.648 * 10^9 Hz) = 1.302083 * 10^-10 seconds
Please note that these calculations are based on the assumption that the PLLDIV is set to 1. If there is additional information available about the PLLDIV, please provide it to get more accurate results.