Altera board

Is there anywhere I can learn altera board programming like statements:

IOWR_ALTERA_AVALON_SPI_TXDATA(SPI_RADIO_BASE, address)?

Also how to have 4-bit SPIs in the SOPC builder. We need to set up a load signal of SPI which asserts evey 4 cycles to signal loading. But I cannot find 4-bit SPIs in the SOPC builder.

Thank you