Currently the hardware supports both 460.8k and 230.4k. All baudrates within 1% of these values are
supported, since successful communication can still occur if you're off by as much as 2% (1% for each partner). One option is to use a custom oscillator value. Instead of the 7.3728 Mhz Oscillator, you can use a 8 Mhz Oscillator. Thus when you set the baudrate to 230.4k programatically, the hardware will operate at 250k.
