A printing apparatus conveys a printing medium in a first direction, and includes an encoder that outputs a predetermined signal in accordance with a conveyance amount of the printing medium in the first direction, and a print head having a plurality of nozzle rows, each of which includes a plurality of nozzles ejecting ink, arrayed in a second direction intersecting with the first direction. In addition, a print engine is connected with the print head and performs conversion processing from image data into print data. The print engine has a first buffer storing the image data, has a second buffer storing the print data, and converts image data stored in the first buffer into print data in response to a first interrupt signal based on the predetermined signal output from the encoder, and stores the print data in the second buffer.