TXS0104E: Push Pull or Open Drain configured

dear

   TXS0104E for serial port level conversion problems, 3.3V system and 1.8V system serial port data conversion, 2Mbps serial port communication rate, the impact on the stability of the system?  There is a description in the chip Data: "Max Data Rates -- 24 Mbps (Push Pull) -- 2 Mbps (Open Drain)". How is the Push Pull or Open Drain configured  

any advise?thanks in advance