To provide a technology of detecting an abnormal state (output short circuit state and input-open state) of an external terminal without increasing costs in a semiconductor integrated circuit.

The semiconductor integrated circuit (MCU) includes a plurality of I/O circuits (IO1 to IO4), a monitor target designating circuit (DPSEL), and an abnormality detecting circuit (PCDET). The plurality of I/O circuits (IO1 to IO4) are provided corresponding to a plurality of external terminals (P1 to P4). The monitor target designating circuit (DPSEL) variably designates a monitor target external terminal from among the plurality of external terminals (P1 to P4). The abnormality detecting circuit (PCDET) detects the output short circuit state of the monitor target external terminal when the I/O circuit corresponding to the monitor target external terminal functions as an output circuit, and detects the input-open state of the monitor target external terminal when the I/O circuit corresponding to the monitor target external terminal functions as an input circuit.

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