SYSCFG_SR1 register
RFIP_BUSY_STATUS | RFIP_BUSY_STATUS: MR_SUBG BUSY status: Software should check that MR_SUBG IP is not busy (or relay on the related interrupt) before to initiate any system clock frequency switch to operate the switching in a safe way. 0: MR_SUBG is not busy. 1: MR_SUBG is busy |