HE83138 Overview
Pin # Pin name 78 77 FXI, FXO I/O Function Description 81 80 SXI, SXO 76 RSTP_N External fast clock input/output Mask Option setting: B, pins are used to connect crystal or MO_FCK/SCKN= 00 : Slow Clock only O RC to generate the 32.768KHz ~ 01.