https://developer.mbed.org/forum/mbed/topic/5205/
-## 'clock_prescale_set' and 'clock_div_1' not available
+## `clock_prescale_set` and `clock_div_1` not available
Your toolchain is too old to support the MCU. For example WinAVR 20100110 doesn't support ATMega32u2.
```