Integrated circuits with test structures including bi-directional protection diodes

Integrated circuits that include bi-directional protection diode structures are disclosed. In one example, an integrated circuit includes a test circuit portion for testing the functionality of the integrated circuit during or after fabrication of the integrated circuit. The test circuit portion includes first, second, and third diode structures and a resistor structure. The first and third diode structures are in parallel with one another and in series with the resistor, and the resistor and the first and third diode structures are in series with the second diode structure. The first and third diode structures are configured for current flow in a first direction and the second diode structure is configured for current flow in a second direction that is opposite the first direction.