Analog/digital conversion circuit, semiconductor device, and electric power steering controlling unit

The present invention provides a method in which a counting source is provided in data after analog/digital conversion to lessen a load placed when new and old data after the conversion are compared to each other. A log function is prepared in an A/D conversion controlling circuit. The log function latches the output of a counter in a 12-bit digital/analog converter at the timing of outputting a pulse from a comparator to determine data written into a data register group. In the case where a setting item related to log output in an ADCR is set at 1, not only the output of the 12-bit digital/analog converter, but also the output of a timer counter of an MTU is latched as a log.