pub type MCO_W<'a> = FieldWriter<'a, u32, CFGR_SPEC, u8, MCO_A, 3, 24>;
Field MCO writer - Microcontroller clock output
MCO
MCO output disabled, no clock on MCO
System clock selected
HSI oscillator clock selected
HSE oscillator clock selected
PLL clock selected (divided by 1 or 2, depending en PLLNODIV)