Electronic control device and microcomputer control method
AssigneeToyota Jidosha Kabushiki Kaisha
InventorNaoki Matsushita
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Abstract
Provided are an electronic control device and a microcomputer control method not only enabling smooth transmission and reception of signals by using a plurality of microcomputers but also capable of achieving, with a simpler configuration, reduction of power consumed by the microcomputers. As a mode for reducing power consumption, the electronic control device brings microcomputers from which a sleep request has been issued into a sleep state. The electronic control device is equipped with a low power consumption mode for bringing a communication bus driver into the sleep state after all microcomputers constituting the electronic control device have been transferred into the sleep state.
Claims15
An electronic control device, comprising a plurality of microcomputers, wherein the electronic control device communicates with other devices through communication lines, wherein
- the microcomputers share a communicator, which is provided between the microcomputers and the communication lines and adapted to transmit and receive signals,
- a power saving mode is performed to reduce power consumed by the electronic control device, wherein the power saving mode is a mode during which any of the microcomputers that have made a sleep request are switched to a sleeping mode, and the communicator is switched to the sleeping mode after all the microcomputers have shifted to the sleeping mode,
- each of the microcomputers includes a standby terminal whose condition is selectively set to “H” logic level, “L” logic level or high impedance in relation to the communicator, and
- the communicator shifts to the sleeping mode when any one of the standby terminals of the microcomputers is set to the “L” logic level.
A method of controlling a plurality of microcomputers included in an electronic control device adapted to conduct communication with other devices, the method comprising:
- causing the microcomputers to share a communicator provided between communication lines and adapted to transmit and receive a signal;
- and
- switching the electronic control device to a power saving mode during which power consumed by the electronic control device is reduced, wherein
- the switching of the electronic control device to the power saving mode includes:
- a first step during which microcomputers for which sleep requests are made are switched to sleeping mode;
- and
- a second step during which the communicator is switched to the sleeping mode after all the microcomputers have shifted to the sleeping mode, wherein the method further includes:
- providing each of the microcomputers with a standby terminal whose condition is selectively set to “H” logic level, “L” logic level or high impedance in relation to the communicator;
- and
- shifting the communicator to the sleeping mode when any one of the standby terminals of the microcomputers is set to the “L” logic level.
Dependencies are inferred from the claim text.