STM32F303RET Clock Issue

[bradbas]

I have a design that I have used in the past but a latest build I am having trouble with the system clock. I am using 8mhz crystal, IOC file HSE is setup to use the crystal. I cannot get the processor to run above 16 Mhz. I have older projects that use the same processor and no issue with running at max 72Mhz. I have this problem with 1.12 and 1.19 so I don't believe it's CubeIDE. Is there any known issues with these chip? 

[AScha.3]

>Is there any known issues with these chip? 

No, afaik.

+

show your x.ioc , Clocktree in Cube ;

like this:

[TDK]

What symptoms are you seeing? Show your schematic.

[bradbas]

[bradbas]

Here is the processor side of the project. Keep in mind this identical configuration in the past year has worked at 72Mhz no problem.

[bradbas]

The processor goes into a strange state and I need to use the CubePGMr to do a full chip erase to bring it back to where I can do another debug session. When debugging it locks up when stepping over SystemClock_Config(); function.

[AScha.3]

And if you set it to its typ. 72 M , as in my clocktree , then ..what ?

+

>Keep in mind this identical configuration in the past year has worked at 72Mhz 

On same board ? or just similar design?

(because from your schematic, no decoupling caps etc. visible .)

[bradbas · Accepted solution]

Update,

Figured it out. My circuit was the same as past but not the power supply. Turns out my 3V3 supply was actually running at 2.0 and once the processor loading got up due to increasing clock speed it dropped below 2.0 which would then make the core unstable. Moral of the story always check your power rails. Thanks everyone.