9 Bit Serial communication

Hi All

I need to talk to a serial device that uses a rather strange serial packet structure. It needs 9 bits where the 9th bit acts as a wake up bit to tell the device that it is being addressed where subsequent commands then have 9th bit as zero.

On the arduino platform I achieved this by directly manipulating the register that controls the parity bit. From chapter 27 of the RM0008 peripheral manual for the STM Micro it seems that the hardware USART is capable of 9 bit serial. How do I unlock this functionality from within the spark dev environment ?