ADDRESS DESIGNATING DEVICE OF DATA PROCESSING DEVICE

PURPOSE:To obtain various execution addresses easily, by counting up the start address of data to be stored and processed one by one and by setting data to be calculated by a program. CONSTITUTION:A DMA (direct memory access) transfer start address and byte length of transfer data are set to a DMA controller 1. Meanwhile, data obtained by subtracting 1 from arithmetical data of the execution address is preset to a preset register 7 from a data bus 10 before the start of DMA transfer. An address register 11 is cleared to zero before DMA start, and the output of a parallel adder 4 is inputted to the register 11 each time DMA transfer for one-byte data is terminated. The adder 4 adds preset data of the register 7 and data of the register 11, and a parallel adder 5 adds the addition result of the adder 4 and the designation address from the controller 1. The output of the adder 5 is used as the execution address.