I'm familiar with SPI bus from other projects and wikipedia, it usually has four signals, SPI_MOSI, SPI_MISO, SPI_CLK, and SPI_CS
however from the datasheet I've only found the VSPICLK and VSPICS0.
I've kinda gleamed that
VSPIQ is SPI_MISO nad
VSPID is SPI_MOSI.

but what is VSPIHD?