Bus operation with integrated circuits in an unpowered state

A television apparatus, comprising:

• a bus coupled to a first power supply;
• an input for receiving television signals;
• a display including deflection circuitry;
• a micro-controller coupled to the bus, the micro-controller recognizing a first predetermined voltage level as logic HIGH;
• a first processing circuit coupled to the bus, the input and the display, the first processing circuit receiving the television signals and generating output signals to drive the display, the first processing circuit recognizing the first predetermined voltage level as logic HIGH;
• a second processing circuit coupled to the bus;
• wherein
• the second processing circuit recognizes a second predetermined voltage level that differs from the first predetermined voltage level as logic HIGH, the second processing circuit is coupled to the bus via an interface circuit that translates voltage level to allow interoperability of the second processing circuit with the micro-controller and the first processing circuit, the second processing circuit and the interface circuit each being coupled to first and second RUN power supplies, respectively, and wherein upon a loss of the RUN power supplies, the loading placed on the bus by the interface circuit and the second processing circuit is controlled in a manner that enables the micro-controller and the first processing circuit to continue to communicate with each other via the bus, whereby the micro-controller is able to turn OFF the first processing circuit prior to reactivating the RUN power supplies.

A network, comprising:

• a bus coupled to a first power supply;
• a first electronic device coupled to the bus, the first electronic device recognizing a first predetermined voltage level as logic HIGH;
• a second electronic device coupled to the bus, the second electronic device recognizing the first predetermined voltage level as logic HIGH;
• and
• a third electronic device coupled to the bus, wherein
• the third electronic device recognizes a second predetermined voltage level that differs from the first predetermined voltage level as logic HIGH, the third electronic device being coupled to the bus via an interface circuit that translates voltage levels to allow interoperability between of the third electronic device with the first and second electronic devices, the third electronic device and the interface circuit each being coupled to a RUN power supply, and wherein upon a loss of the RUN power supply, the loading placed on the bus by the interface circuit and the third electronic device is controlled in a manner that enables the first electronic device and the second electronic device to continue to communicate with each other.