System Clock & RF Packet Baud Rate

Hi All,

I use CC1110 SoC. I wonder how to decide that which system clock is minimum clock value for any RF packet baud rate.

It is said that minimum system clock can be 203.125KHz for 10Kbaud and 1.625MHz for 250Kbaud in Datasheet and DN111 while waiting in RX mode for RF packet. Why required minimum system clock for 250Kbaud is 1.625MHz? How can i calculate required minimum system clock?

Thanks.