PLLR: PLL division factor for I2S, SAI, SYSTEM, SPDIFRX clocks. This parameter is only available in STM32F410xx/STM32F446xx/STM32F469xx/STM32F479xx and STM32F412Zx/STM32F412Vx/STM32F412Rx/STM32F412Cx/STM32F413xx/STM32F423xx devices. This parameter must be a number between Min_Data = 2 and Max_Data = 7