Integrated circuit device, electro-optical device, and electronic instrument

An integrated circuit device comprising:

• a high-speed serial interface circuit that includes a receiver circuit that receives differential signals through a serial bus;
• a first guard terminal that prevents radiation;
• a second guard terminal that prevents radiation;
• a first terminal that is disposed between the first guard terminal and the second guard terminal and receives a first signal of the differential signals;
• a second terminal that is disposed between the first guard terminal and the second guard terminal and receives a second signal of the differential signals;
• a first power supply terminal, a high-voltage-side power supply voltage of the receiver circuit being supplied to the first power supply terminal;
• a second power supply terminal, a low-voltage-side power supply voltage being supplied to the second power supply terminal;
• a first switch element provided between a line from the first guard terminal and a line from the second power supply terminal;
• a second switch element provided between a line from the second guard terminal and a line from the second power supply terminal;
• a first I/O buffer that receives and outputs a parallel interface signal through the first guard terminal;
• and
• a second I/O buffer that receives and outputs a parallel interface signal through the second guard terminal,
• the first switch element and the second switch element being turned ON and outputs of the first I/O buffer and the second I/O buffer being set at a low-voltage-side level or set in a high impedance state in a high-speed serial interface mode.