Data flow processor and data flow process changing system

Data processing apparatus comprising:

• a data flow process changing system comprising destination number storage means storing a plurality of different destination numbers, data input means for receiving successive input data units, counter means connected for counting, and assigning a successive count number to, each successive input data unit received by said data input means, with each count number being associated with a selected destination number, means for combining each received input data unit with a respective one of the plurality of destination numbers to form a respective packet, said means for combining being controlled by the count number assigned to each input data unit for combining each input data unit with the selected destination number which is associated with the assigned count number, and output means for outputting each packet, and
• a data flow processor comprising packet input means connected to said output means for receiving each packet, a program storage section storing a plurality of programs, the programs including a main program which executes a process utilizing a constant, and a constant change program which executes a process for updating the constant utilized in the process executed by the main program, each program corresponding to a respective one of the destination numbers stored in said destination number storage means, and a processing section connected to receive the data unit in each packet received by said packet input means and to process the received data unit in each packet under control of that one of the stored programs which corresponds to the destination number in the same packet.