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STR71X CLOCK CONFIGURATIONS EASY SETUP

1 PRCCU

This peripheral allows the configuration of the clock Prescaler values to adjust the needed fre-

quencies for the CPU, the APB1 and the APB2.

This peripheral contains two calculation sheets:

■

CCU: Clock Control Unit calculation

■

CDU: Clock Distribution Unit calculation

1.1 CCU

In this calculation sheet, it is necessary to enter the input clock frequency and the PLL config-

uration parameters (the Prescaler ratio, the PLL multiplier ratio, the PLL divider factor, the

input clock source and the running mode).

Figure 1. CCU calculation sheet

This sheet calculates all the frequencies which can be generated by the PLL.

As an example, as shown in Figure 1, the input frequency is set to 16MHz, the Prescaler ratio

(1/2) is activated, the multiplier ratio is set to 20, the divider factor is set to 4 and the PLL is

locked. This configuration allows the RCLK frequency to be set to 40MHz.

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