32 PTB0 - SCL0 (add header pin, label as SCL0)
33 PTB1 - SDA0 (add header pin, label as SDA0)
35 PTB16 - SDB (tied to all Chips, hardware shutdown)
49 PTA19 (LED only for PCB, not McHCK) (XTAL)
76 PTA1 (Not broken out on PCB, available on McHCK) (Pull-up)