1. A data display method comprising the steps of: receiving data having a program unit and instruction data for the program unit multiplexed on bit stream data; extracting the program unit from the received data and storing the extracted program unit in a memory; extracting the instruction data from the received data, reading the program unit or part thereof specified by the extracted instruction data from the memory, and executing the read program unit or the part thereof; and displaying the bit stream data and the execution result.