Resolved! References to TIM5 in RM0091
There is no TIM5 in the 'F0.Textual search for TIM5 in RM0091 rev.9 reveals it occurs twice:in Internal clock source (CK_INT) subchapter of TIM15/16/17 chapter; this is a typo and it ought to be TIM15 (because TIM16/17 don't have the slave-mode contr...