A program controlled processor comprises a scalar processing unit 101 for normal data (= scalar) operations and branch processing, a plurality of vector processing units 102 of identical structure, a vector distributor 103 for distributing input data as block vectors to vector memory 304 in each vector processing unit 102, a vector coupler 104 for coupling the block vectors stored in vector memory 404 in each vector processing unit 102 to provide output vectors, an instruction memory 105 for storing the operations of these circuit blocks as an operating program, a sequencer 106 for sequentially reading the instruction memory 105, and a decoder 107 for interpreting the read instructions and outputting a control signal to each circuit block. The scalar processing unit 101 comprises a scalar bus input enabling the scalar processing unit 101 to refer scalar registers in the vector processing units 102. The program controlled processor has improved data processing performance because parallel vector instructions are operated in parallel in the vector processing units of block data distributed by the vector distributor.