Viewing the UART registers for bps settings,
a) the Keil baudrate claculator will give you the correct timer values
b) transmit 'U' (capital U) in an endless loop and your scope will show 1/2 bps as the frequency

data written to the crossbar,
XBRn in the SFR window.

data written to the scratch pad area to perform math calculations
the scratchpad is flash and "limited lifetime" I would not use it for calculations, Are you talking of the scratchpad in the SILabs flash or something else.

Erik