Semiconductor device configured to detect an abnormality of an external oscillation signal, display apparatus, and vehicle

A semiconductor device, comprising:

• an external terminal configured to accept an external input of an external oscillation signal;
• an internal oscillation portion configured to generate an internal oscillation signal;
• a logic inversion detection portion configured to generate a reset signal upon detecting logic inversion of a first internal signal corresponding to the external oscillation signal;
• a monitor counter configured to increase or decrease a count output value in accordance with the internal oscillation signal and to reset the count output value in accordance with the reset signal;
• and
• an abnormality detection portion configured to detect, in accordance with the count output value, whether or not there is an abnormality in the external oscillation signal;
• and
• an oscillator configured to generate an internal clock signal based on one of the external oscillation signal and the internal oscillation signal,
• wherein the oscillator includes
• a selector configured to output, as a selected oscillation signal, one of the external oscillation signal and the internal oscillation signal, and
• a frequency divider configured to generate the internal clock signal from the selected oscillation signal.