At CPOL=0 the base value of the clock is zero
For CPHA=0, data are captured on the clock's rising edge (low→high transition) and data is propagated on a falling edge (high→low clock transition).
For CPHA=1, data are captured on the clock's falling edge and data is propagated on a rising edge.
At CPOL=1 the base value of the clock is one (inversion of CPOL=0)
For CPHA=0, data are captured on clock's falling edge and data is propagated on a rising edge.
For CPHA=1, data are captured on clock's rising edge and data is propagated on a falling edge