External Ports - 3.0 English - PG448

GPIO and UART signals should be connected as GPIOs.

SMBus/I2C signals should be connected in the following way (see the following figure):

1. External ports should be open-drain tri-state I/O.
2. Inputs smb_scl_in and smb_sda_in should be connected to their corresponding I/O.
3. Outputs smb_scl_oe and smb_sda_oe should be connected to the tri-state control of the I/O, where the input of the tri-state buffer should be connected to logical zero.
4. If smb_scl/sda_oe = 0 then I/O = 0, else I/O = High Z