I am programming an STM32 (manual here). Page 83 has a diagram indicating that the HSE Clock frequency is between 4 and 26 MHz.
The paragraph on HSE clocks starts on page 84, but does not give any information regarding setting the clock to a specific frequency. I have had a look at the RCC registers (starting from page 91) and could find how to turn on/off several clocks, and set various prescalers. I haven't found any register dealing with setting and reading the HSE clock frequency.
How can I read/write the HSE clock frequency?