I use an external 8.0 Mhz crystal connected to the HSE pins. I use STM32F2xx_Clock_Configuration_V1.1.0.xls utility with HSE_OSC setting to 8.0 MHz and HCLK setting to 120.0 MHz and let generate the file system_stm32f2xx.c .
In my application I output some text on the USART2.
Sometimes when I power up my system it is working normally so my text is output with the correct baud rate. In other cases powering up the system the text is output with a much lower baud.
I have programmed the MCO2 pin, so that it is outputting the signal SYSCLK divided by two. In the cases when my system is working normally I measure on this pin with the scope 60 MHz. In other cases when the system is working abnormally, then I measure there 8.0 MHz.
It seems that something is going wrong with the PLL setup in the cases, when my system is working abnormally.
On the GUI of the STM32F2xx_Clock_Configuration_V1.1.0.xls utility they state that it is for RevB and RevY silicon. Actually I have RevX silicon. Is this the cause of my problem that the utility doesn’t support RevX silicon ?