Integrated circuit system and integrated circuit

An integrated circuit for operating in an operation mode that is at least either an active mode or a sleep mode, comprising:

• a plurality of I/O ports configured to transmit or receive signals based on signal modes which are set to the plurality of I/O ports;
• and
• a control circuit configured to set, in the active mode, the signal modes of the plurality of I/O ports,
• wherein the signal modes set to the plurality of I/O ports in the active mode are maintained in the sleep mode,
• wherein a first notification signal that indicates an operation mode is transmitted to an outside through one of the plurality of I/O ports,
• wherein a second notification signal that indicates an operation mode of another integrated circuit is received through one of the plurality of I/O ports,
• wherein the control circuit sets the signal modes of the plurality of I/O ports based on the second notification signal to suppress steady currents persistently flowing between the plurality of I/O ports and said another integrated circuit, and to suppress through currents flowing at the plurality of I/O ports, and
• wherein in a case of the second notification signal indicating a transition of said another integrated circuit to a sleep mode, the control circuit sets the plurality of I/O ports to a push-pull output mode, a pullup input mode, or a pulldown input mode.

An integrated circuit for operating in an operation mode that is at least either an active mode or a sleep mode, comprising:

• a plurality of I/O ports configured to transmit or receive signals based on signal modes which are set to the plurality of I/O ports;
• and
• a control circuit configured to set, in the active mode, the signal modes of the plurality of I/O ports,
• wherein the signal modes set to the plurality of I/O ports in the active mode are not maintained in the sleep mode, and the plurality of I/O ports are placed in a floating state in the sleep mode,
• wherein a first notification signal that indicates an operation mode of another integrated circuit is received through one of the plurality of I/O ports,
• wherein a second notification signal that indicates an operation mode is transmitted to an outside through one of the plurality of I/O ports,
• wherein the control circuit sets the signal modes of the plurality of I/O ports based on the second notification signal to suppress steady currents persistently flowing between the plurality of I/O ports and said another integrated circuit, and to suppress through currents flowing at the plurality of I/O ports, and
• wherein the control circuit transmits the second notification signal indicative of the sleep mode to an outside when a transition is made from the active mode to the sleep mode.