A data processing apparatus may include a data conversion unit for, when converting a plurality of sequentially input data into conversion data of the same bit number as a data bus having a prescribed bit number and sequentially transferring the conversion data, arranging the input data in each conversion unit using the conversion data as one transfer unit and a prescribed number of transfer units as one conversion unit. The data conversion unit may include a first data generation unit, a second data generation unit for generating second data obtained by allocating a prescribed second number of input data in the input data not allocated to the first data, to the second bit range and a data coupling unit for coupling the first data and the second data to generate the conversion data having the bit number of the bus width of the data bus.