I am also looking at implementing an SPI interface, in my example it is to log gyroscope data.
I have posted my simple, example program (spi arm.zip) at this site: ftp://ftp.ni.com/outgoing (It will be available for 48 hours.)
For those who come across this posting after the 48 hours, here are screenshots of my example program. It's written for the MCB2300 using the LabVIEW Embedded Module for ARM, version 8.5.1. This example shows how to communicate between the MCB2300 and an external SPI (Serial Peripheral Interface) bus device.
I implemented a simple command to read from my external device. You'll have to tailor the command you send depending on your external SPI bus hardware.