Abstract: In a clock-synchronous communication system, a clock pulse as a communication clock is outputted from a master device to a slave device so as to synchronize the master device and slave device. The transmitting side transmits a data to a data line with a first edge timing of the clock pulse, and the receiving side receives the data from the data line with a second edge timing of the clock pulse. A microcomputer as the master device is configured to enable separate setting of high-level duration and low-level duration of a clock pulse to be outputted, using a program. High-level duration and low-level duration are each set to a minimum value that satisfies the requirements for constituting communication with a communication destination. Uprating not only the cycle of a clock pulse but also the communication baud rate, efficient clock-synchronous communication can be performed.

Abstract: In a clock-synchronous communication system, a clock pulse as a communication clock is outputted from a master device to a slave device so as to synchronize the master device and slave device. The transmitting side transmits a data to a data line with a first edge timing of the clock pulse, and the receiving side receives the data from the data line with a second edge timing of the clock pulse. A microcomputer as the master device is configured to enable separate setting of high-level duration and low-level duration of a clock pulse to be outputted, using a program. High-level duration and low-level duration are each set to a minimum value that satisfies the requirements for constituting communication with a communication destination. Uprating not only the cycle of a clock pulse but also the communication baud rate, efficient clock-synchronous communication can be performed.

Abstract: An electronic control apparatus has a memory which stores a map consisting of a set of map points and corresponding set of map values, with the map values representing respective physical quantity values, and at least one of the sets of map points and map values being stored as fixed-point representation data. When a map point is specified, the apparatus obtains a corresponding physical quantity value by converting fixed-point data of the map to floating-point representation, then using a floating-point arithmetic unit to perform an interpolation calculation using the converted data.

Abstract: In a method, an interrupt is generated to the processing unit every predetermined period. The predetermined period is shorter than a predetermined timeout period. A watchdog signal is changed in response to each of the generated interrupts. The interrupt generation is disabled, upon the last interrupt being generated over an estimated time when the execution of the program is estimated to be completed.

Abstract: In a method, an interrupt is generated to the processing unit every predetermined period. The predetermined period is shorter than a predetermined timeout period. A watchdog signal is changed in response to each of the generated interrupts. The interrupt generation is disabled, upon the last interrupt being generated over an estimated time when the execution of the program is estimated to be completed.

Abstract: A computation processing is repeatedly executed in a control program. In the processing, a preceding computation result RamA that is represented as a floating point mode is used for computation of a current result RamA. Whether the preceding computation result RamA is either of non-numeral and infinity is determined. When the preceding computation result RamA is either non-numeral or infinity, the processing does not proceed to next computation but substitutes a default value for a variable RamA. Here, the processing substitutes a target value for the variable RamA if the variable RamA has a characteristic of converging on the target value in the computation processing.

Abstract: An electronic control apparatus has a memory which stores a map consisting of a set of map points and corresponding set of map values, with the map values representing respective physical quantity values, and at least one of the sets of map points and map values being stored as fixed-point representation data. When a map point is specified, the apparatus obtains a corresponding physical quantity value by converting fixed-point data of the map to floating-point representation, then using a floating-point arithmetic unit to perform an interpolation calculation using the converted data.

Abstract: A computation processing is repeatedly executed in a control program. In the processing, a preceding computation result RamA that is represented as a floating point mode is used for computation of a current result RamA. Whether the preceding computation result RamA is either of non-numeral and infinity is determined. When the preceding computation result RamA is either non-numeral or infinity, the processing does not proceed to next computation but substitutes a default value for a variable RamA. Here, the processing substitutes a target value for the variable RamA if the variable RamA has a characteristic of converging on the target value in the computation processing.