The cristal CL is really the series value of CL1 and CL2 for cristal oscillator circuit for STM32 MCUs?

[Aldo_Flores_Aguayo]

I was searching for a optimal cristal for my MCU and in the specs of HSE for my MCU (STM32F103) i found this highlighted in yellow 

Then in the guide shown below 

 

I saw and exampe but this doesnt match with the stated in the datasheet because of the following 

Here the CL1 and CL2 series equivalent is 5pF but the CL of the cristal is 8pF so I dont know if Im missing something or is that this condition is not always true, hope some one can help me to clarify this, thanks!! 

[STOne-32]

Dear ​@Aldo_Flores_Aguayo ,

There is no conflict between both references. Here is the general rule :

CL1=CL2 =2 *CL ( of crystal) 

 

So if your crystal datasheet has 8MHz and CL=8pF

CL1 and CL2 should be in range of 16pF, But due to PCB and pins parasitics we can assume about Cs=3pF.  So your CL1=CL2 =2 * ( 8-3) = 10pF is a good starting point for your design .

Regards,

STOne-32