We have some basic examples written in assembly coming along with the Evaluation-CD.
Sorry nothing in C.
But the examples are very small and straight forward and can be easily transferred to C by a SW engineer.
The main point is how to configure the SFRs – this can be seen in the assembly examples easily.
Here an example for a SPI Master configuration:
; CONFIGURE SPI...
MOV SPICON,#037h ; configure SPI port for:
; Fosc/16, CPHA=1, CPOL=0, master
MOV IEIP2,#1 ; enable SPI interrupt
Hope that helps.