A data processing apparatus and a program data setting method that can minimize a manufacturing cost. The data processing apparatus includes a plurality of In System Programming (ISP) devices to store program data used to drive the data processing apparatus, a connector to receive the program data from an external program providing device, and a switch to switch a connection between the connector and the plurality of ISP devices. The data processing apparatus can adjust the connection between the connector and the plurality of ISP devices using the switch. Accordingly, the data processing apparatus does not require an additional connector or a separate program to distribute the program data received at the connector to each ISP device so that the manufacturing cost can be minimized and a structure can be simplified.