A data driven information processor includes an operation processor unit for prestoring a data flow program and carrying out processing, and a storage microprocessor unit having a plurality of data memories including external data memories for inputting/outputting data to and from the operation processor unit. In the storage microprocessor unit, a plurality of data memories are accessed, in parallel, based on the content of an applied data packet for a single access time. The result of each access is operated in accordance with the content of the data packet. Finally, the subsequent program is read from a data flow program prestored in the storage microprocessor unit so that access to the plurality of data memories and processing of a result of the access continue in the storage microprocessor unit. Thus, in the information processor, parallel access to a plurality of data memories can be achieved by program control independent of program control by the operation processor unit.