Electronic control apparatus
AssigneeDenso Corporation
InventorEiji Sugitachi
Life of this patent
Estimating the term…
Abstract
In an electronic control apparatus, a microcomputer stops its operation when a power voltage supplied from a regulator starts to fall. When a low voltage detection circuit detects fall of the power voltage, the microcomputer is reset immediately and a communication start detection circuit is permitted to output a communication start signal. It is also possible to maintain the microcomputer in a wait state until proceeding to a sleep mode, and proceed to a normal operation mode when a power-on start signal is changed to be active in a period of the wait state.
Claims8
An electronic control apparatus comprising:
- a control circuit for controlling a control object device;
- a communication driver for transforming signals applied thereto for communication between the control circuit and an external apparatus through a communication bus;
- a check circuit for checking whether the communication has started through the communication bus;
- a latch circuit for latching a communication start signal outputted from the check circuit;
- a power circuit for generating a power voltage, which is supplied to the control circuit in accordance with a control signal outputted from the control circuit or the communication start signal applied through the latch circuit;
- and
- a low voltage detection circuit for detecting fall of the power voltage below a predetermined threshold level,
- wherein the control circuit is reset and the check circuit is permitted to output the communication start signal, by the low voltage detection signal outputted from the low voltage detection circuit.
An electronic control apparatus comprising:
- a control circuit for controlling a control object device;
- a communication driver for transforming signals applied thereto for communication between the control circuit and an external apparatus through a communication bus;
- a check circuit for checking whether the communication has started through the communication bus;
- a latch circuit for latching a communication start signal outputted from the check circuit;
- a power circuit for generating a power voltage, which is supplied to the control circuit when a power-on start signal becomes active, the power-on start signal becoming active when a control signal outputted from the control circuit becomes active or the communication start signal applied through the latch circuit becomes active;
- and
- a low voltage detection circuit for detecting fall of the power voltage below a predetermined threshold level,
- wherein the control circuit changes the control signal applied to the power circuit to be inactive when a condition for changing from a normal operation mode to a sleep mode is satisfied under a condition that a power-on start signal is applied, then is reset by the low voltage detection signal of the low voltage detection circuit to remain in a wait state until proceeding to the sleep mode, and proceeds to the normal operation mode when the power-on start signal is changed to be active in a period of the wait state.
Dependencies are inferred from the claim text.