| 摘要 |
PURPOSE:To prevent the runaway of a DSP by providing a flag register for indirect jumping and executing a next instruction without executing an indirect jumping instruction when the contents exceed the specified number of contents. CONSTITUTION:A flag register 34 for indirect jumping is provided, when respective instructions stored in an instruction memory 2 are executed, first, in the address A', the value of the register 34 is made into '0', and in an address A of an instruction memory 1, a jumping address a1 is set to an address M of a data memory 2. When the indirect jumping instruction is executed in an address B of the instruction memory 1, it can be judged by the contents of the register whether or not execution is performed. Namely, when a deciding part 55 decides that the contents of the register 34 exceed a specified value, the jumping address set to the memory 2 is not outputted, B+1 is outputted in which '1' only is added to the address B, and the instruction stored in a next address B+1 of the address B, in which the indirect jumping instruction of the instruction memory 1 is stored, is executed. |
