| 摘要 |
PURPOSE:To easily expand a function by ASIC(application specific integrated circuit) expansion by providing an interface means which connects an internal data bus to outside not through a bus interface. CONSTITUTION:A digital signal processor 1 outputs register specification information and access control information included in the decoded information of a register transfer instruction from an instruction decoder 2 to outside. Further, the interface means 20 connect the internal data bus 12 included in an arithmetic execution system not through the external bus interface 11. Then, data transfer to the outside which is passed through the interface means 20 is carried out by supplying a dedicated data transfer instruction like a register transfer instruction to an instruction decoder 2. Consequently, when the ASIC expansion which uses the processor as a core unit is performed, a necessary function is added selectively like the addition of another circuit unit. |
