Clock Stretching Sequence
If FLEX_TWI_THR or FLEX_TWI_RHR is not written/read in time, the TWI performs a clock stretching.
Clock stretching information is given by the SCLWS (Clock Wait State) bit.
See figures "Clock Stretching in Read Mode" and "Clock Stretching in Write Mode" below.
Note: Clock stretching can be disabled by configuring the FLEX_TWI_SMR.SCLWSDIS bit. In that
case, UNRE and OVRE flags will indicate underrun (when FLEX_TWI_THR is not filled on time)
or overrun (when FLEX_TWI_RHR is not read on time).