STM32F4 Discovery HSE issue

[A_H]

Hi,

I am new user of ST Microcontrollers. I am using STM32F4 Discovery board.

Till now its default HSI oscillator I was using, now I am going to use the HSE clock of this.

STM32F4 Discovery board have 8 MHz crystal, which is connected to the microcontroller. when I goto configure through STM32 CUBEMX configuration tool then it shows me a RED lndicator and it shows that clock must be greater than 14.2MHz.

Why it is so? Datasheet says that we can use clock frequency ranging from 4-26MHz.

Can someone explain me this? How to resolve this issue?

[waclawek.jan]

At such low AHB frequency you can't use USB.

JW

[A_H]

I am not using USB feature right now. I am in learning phase and just want to check this HSE configuration.

Can I go with these settings? 

for USB or any other peripheral definately I will use the higher clock.

[AScha.3 · Accepted solution]

Hi,

>How to resolve this issue?

There is no issue - you just have to disable/not use anything, that needs a higher clock, like I2S, USB etc.

see:

[A_H]

Thanks all of you for your support