A citation from "RM0041. Reference manual. STM32F100xx":
OSSI: Off-state selection for Idle mode
This bit is used when MOE=0 on channels configured as outputs.
0: When inactive, OC/OCN outputs are disabled (OC/OCN enable output signal=0).
1: When inactive, OC/OCN outputs are forced first with their idle level as soon as CCxE=1 or
CCxNE=1 (OC/OCN enable output signal=1).
But. My experiments on STM32F100RB have shown that this bit has no effect on the state of the outputs.
Can someone have an example of using the OSSI bit?