Baseboard ID
From embeddedTS Manuals
All of our default baseboards contain a hard wired 3-state 8-input multiplexers. This is not required to implement in custom baseboards, but it can be useful to identify the board in software. During startup of the macrocontroller 4 DIO are used to obtain the baseboard model id. The red LED (CN2_06) is state 0, green LED (CN2_08) is state 1, BUS_DIR (CN1_98), and BD_ID_DATA (CN1_83) are used for this purpose.