The clock diagram in RM0316 for the 32F303K8 indicates a clock selection mux off the APBx prescalers. I've searched the registers and cannot find the register used to select one of 4 clock inputs. The 4 possible inputs are the LSE, HSI, SYSCLK, or the clock off the APBx prescaler. The outpu tis to the usuart.
Can someone point me to the register.