A substrate includes a first and a second element arrays in each of which a plurality of elements is arrayed along a first direction of the substrate, a first and a second pad arrays in which a plurality of pads is arrayed along respective two opposite sides extending along a second direction of the substrate, a reception circuit configured to receive data for driving the elements, a data circuit configured to generate data corresponding to the first and the second element array, respectively based on the received data, a signal generation circuit configured to generate a period signal for determining a drive period of the elements based on the generated data, and an output circuit configured to output information related to the substrate.