63.9.5.4.4 Clock Stretching

In both Read and Write modes, it may happen that the FLEX_TWI_THR/FLEX_TWI_RHR buffer is not filled/emptied before the transmission/reception of a new character. In this case, to avoid sending/receiving undesired data, a clock stretching mechanism is implemented.

Note: Clock stretching can be disabled by setting the FLEX_TWI_SMR.SCLWSDIS bit. In that case, the UNRE and OVRE flags indicate an underrun (when FLEX_TWI_THR is not filled on time) or an overrun (when FLEX_TWI_RHR is not read on time).