Patent ID: 7642947

Claim:
A data processing method for acquiring digital data of a multiply-accumulate result of plural processing object signals by comparing, for each of the plural processing object signals, a reference signal, which gradually changes, for converting the processing object signal into digital data and the processing object signal, performing count processing in a designated count period in parallel to the comparison processing, and storing a count value at a point when the comparison processing is completed, the data processing method comprising the steps of: performing, during the count processing for a processing object signal of a subtraction element, the count processing in a period from a point when the processing object signal and the reference signal coincide with each other until a point when the reference signal reaches a predetermined end value; performing, during the count processing for a processing object signal of an addition element, the count processing in a period from a point when the reference signal is a predetermined initial value until a point when the processing object signal and the reference signal coincide with each other; applying the count processing to both the subtraction element and the addition element in an identical mode of any one of an up-count mode and a down-count mode; starting, during the count processing for a following processing object signal, the count processing using a count value stored in the count processing for a preceding processing object signal as an initial value; and correcting the digital data of the multiply-accumulate result to digital data in which a count value corresponding to a period in which the reference signal in the count processing for the processing object signal of the subtraction element reaches the end value from the initial value is corrected.