 Okay, but you can see that the setting everything manually is not so convenient. Then how to do this? I here reset with this button my clock configuration to have the default settings. You can see everything is by default 60 MHz. This is the default settings of the microcontroller after reset. But if I am too lazy to configure everything, I can put here the value and he try for me to calculate the frequency. Now he asking if he can change the clock source because we cannot use for the 84 the HSC as a clock source. Then we click here and he automatically configure the 84, 84 MHz. You can always write the values inside this blue boxes which are around it. I can reset it again to show you that it is really working. I can here type the 42 for example. Again he asking me to change the clock source then I can allow him this feature and it's working. Last part to mention, maybe you can see that not all the functionalities are available like here the second PL which belongs to the I2S. In case that we enable the I2S, again in the pinout if I point here my mouse, you can see the advice to enable the I2S. If I go to the pinout I here enable the I2S, yes here for example into 4 duplex, you can see it's now enabled. Then this is the mystery of the gray unused functions, then you need only to enable this functionality in the pinout tab. And also this is the second part the MCOs. Here are not only inputs which can be used to clock the microcontroller but also you have mainly one or two outputs, depends on the type of the microcontroller and the size of your package which can be used. It's called the MCO1 or 2. And in case again you want to enable this MCOs you need to enable them in the IP in the pinout. Then we go to the pinout, he advice us to go into RCC and here enable the master clock output 1 or 2, I can both. He also reserve for me the pins. And now you can see the multiplexer is active, I can select the output, I directly see the frequency which I have, I can divide also the output. And this allow me to clock some internal circuits. Again for the low speed clock, you can see it again they are not connected to any pay-fay, one is the independent watchdog, second part is the real-time clock. In case that I want to change here this multiplexer I need to enable the real-time clock. I go to the pinout, I hear the real-time clock, for example enable the periodic wakeup system. And I can also enable here the independent watchdog. And you can see now I can set the clock source for the real-time clocks and also the independent watchdog have valid clocks. Okay, only last feature which I forget to mention on this microcontroller, in case that you are using the external high speed clocks, here I change it to the external high speed for the core or for the PLL. Okay, now I using 25 megahertz high speed external oscillator for my core. And you can see that here is available the button, it's called the clock security system. It's used in case that as a clock source is are the external clocks, external clock circuit at least the crystal or the oscillator or the any external frequency. And it's clock source for your PLL or directly for the core. Because in case that the external clock source will fail the microcontroller will be blocked. For this is here the clock security system which can be enabled. And in case that this external clock will fail, the microcontroller will automatically switch to the internal clock source, to the HSE automatically. And the user is notified with the interrupt. That is something wrong, you lose the external clocks, then you can switch into emergency mode for example. Okay, definitely in case you have the different microcontroller type, not the F401 like me, the clock tree will be a little bit different, but the basic clock tree is still very similar. We still have always the PLL, always the system multiplexer, always the AHB Peskeles, APB Peskeles, it's always the same. We only have the multiple outputs from the PLLs, we have more PLLs, but the basic is the same. PLL can multiply the frequency and also divide the frequency. We have the dividers, we have the multiplexers which selecting the clock source. In case the functionality is gray, point there with the mouse and the cubemix will try to advise you what is wrong, what is necessary to enable. In case that you are not happy with your configuration, you can here click on the button to reset the clock configuration. Or here in the clock configuration is to reset, or here is the button to resolve the issues. In case that is something wrong, you here can click to resolve the issues and the cubemix will try for you to solve all the issues. The last part which can be here mentioned, in case you want to do some specific configuration which is related to the many dividers and multiplexers in the row, for example for this timer, I want to have the specific frequency, for example 20 MHz, okay. E for me now configure everything. But I want here to have the different frequency, for example 40, because I can. Then here I can click with the right button and I here set the lock. This means that now the cubemix, if we reconfigure the frequency, he will try here keep always the 20 MHz. You can see now I can try to put here the 40. He reconfigure everything, but here it's always the 20. And I think he never allow me here put the 30, he will try. He will try all the possibilities if it's possible to set this frequency or not. If not, he will notify us or he will advise us the closest frequency which is possible. Then we can left him to search all the possibilities. And you can see there is no possible solution. He can also try use the different clock sources. Now he trying to use also the external one, all the possible combination, but I worry that this is impossible configuration and on the end he will tell us that it's not possible use the microcontroller in this configuration. On the end the cubemix give us possibility to select for here 20 or 40 MHz, it was only only possibility, because the configuration which I put the 30 MHz and 20 it's impossible. And everything it's okay.