/* Set the slave select pins of the specified SPI port. 
The  */
void SPISSSet(unsigned long ulBase, unsigned long ulSlaveSel)
/* Set the slave select pins of the specified SPI port. 
The  */
void SPISSSet(unsigned long ulBase, unsigned long ulSlaveSel)
{
    xASSERT((ulBase == SPI0_BASE) || (ulBase == SPI1_BASE)||
            (ulBase == SPI2_BASE) );
    xASSERT((ulSlaveSel == SPI_SS_NONE) || (ulSlaveSel == SPI_SS0) ||
            (ulSlaveSel == SPI_SS1) || (ulSlaveSel == SPI_SS0_SS1));
    xHWREG(ulBase + SPI_SSR) &= ~SPI_SSR_SSR_M;
    xHWREG(ulBase + SPI_SSR) |= ulSlaveSel;
}