(1) Latch up will not occur id the power to the board is switched on after the connector is plugged in.
(2) Problems can occur if the I2C User Module is started in the firmware. The low level on the lines will cause the I2C Hardware to indefinitely wait for a rising edge.
Thanks for your reply. Just to clarify;
(1) Based on what you are saying, if power is connected to the PSoC and ground is not the first pin to make contact, latchup will probably occur. Is this correct?
(2) If the I2C lines are left floating and the I2C module is not disabled, what exactly happens?
(1) If VDD power supply and some other pins of PSoC are connected before VSS, then latch-up may occur.
(2) If the I2C lines are left floating, and the I2C User Module is enabled, you may get spurious data, and the I2C Module may be put into a non-recoverable state. But no physical damage will occur.