The primary oscillator 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 the Fcy (Internal instruction cycle frequency) and Tcy (Internal instruction cycle time), we need to understand how the PLL (Phase-Locked Loop) affects the clock frequency.
The PLL is a feedback control system that generates an output signal that has a fixed relationship to the phase of the input signal. In this case, it is used to generate a stable clock frequency from the primary oscillator.
Let's assume the primary oscillator provides a clock signal with a frequency of Fosc (7.648 GHz). The PLL will then multiply this frequency by a certain factor (N) to generate the desired Fcy.
The formula to calculate Fcy is:
Fcy = (Fosc × N) / (M × 2 × O)
where:
- Fosc is the frequency of the primary oscillator (7.648 GHz)
- N is the multiplication factor of the PLL (depends on PLL configuration)
- M is the prescaler value (depends on the microcontroller configuration)
- O is the oscillator postscaler value (depends on the microcontroller configuration)
- 2 is the factor due to the PLL being in a divide-by-two mode (depends on the PLL configuration)
Without specific configuration details, we cannot determine the values of N, M, and O. Therefore, we cannot calculate the exact Fcy and Tcy. These values will depend on the microcontroller and its PLL configuration.
If you provide more details about the PLL configuration and microcontroller being used, I can help you further with the calculations.
To find Fcy (Internal instruction cycle frequency) and Tcy, we need to know the division factor (N) of the PLL.
The formula for Fcy is:
Fcy = Fosc / (4 * N)
Given:
Fosc (Primary oscillator frequency) = 7.648 GHz = 7.648 * 10^9 Hz
We need to determine the division factor (N) of the PLL to calculate Fcy and Tcy. If this information is not given, we cannot proceed with the calculation.
Once you provide the division factor (N), I will be able to calculate Fcy and Tcy.
To calculate Fcy (Internal instruction cycle frequency) and Tcy, we need to find the frequency division factor of the PLL and the primary oscillator.
First, we need to determine the PLL frequency division factor (N1) using the formula:
N1 = [F_PLL / (2 * Fosc)] - 1
Where:
F_PLL = 7.648 GHz (PLL frequency)
Fosc = 7.648 GHz (Primary oscillator frequency)
Substituting the values, we have:
N1 = [7.648 GHz / (2 * 7.648 GHz)] - 1
= [1] - 1
= 0
Since N1 is 0, it means there is no frequency division factor between the primary oscillator and the PLL.
Next, we can calculate Fcy (Internal instruction cycle frequency) using the formula:
Fcy = F_PLL / 2
= 7.648 GHz / 2
= 3.824 GHz
Therefore, Fcy is 3.824 GHz.
Finally, we can calculate Tcy (cycle time) using the formula:
Tcy = 1 / Fcy
= 1 / 3.824 GHz
≈ 0.261 ns
Therefore, Tcy is approximately 0.261 nanoseconds.