Tx+1Tx-2GND3VDD4Rx+5Rx-6SEL17VDD8SEL29D+10D-11GND12GND13D-B14D+B15GND16D-A17D+A18OE#19GND20RX-B21RX+B22TX-B23TX+B24GND25Rx-A26Rx+A27Tx-A28Tx+A29GND30VDD31PD32GND33