| 摘要 |
PROBLEM TO BE SOLVED: To reduce and avoid the processing of the data saving/restoration of general-purpose registers, to share the general-purpsoe registers and to avoid the processing speed of a program from lowering. SOLUTION: '1' is set to the respective bit of the selection bits 31, 33, 35 and 37 of the selected general-purpose registers 1, 3, 15 and 17 in a flag register 30. A register selection control part 20 validates only access signal lines 21, 23, 25 and 27 and selects the general-purpose registers 1, 3, 15 and 17 corresponding to the respective bits of the flag register 30. The register selection control part 20 selects the general-purpose register so that it corresponds to the general- purpose register designating the program and the flag register 30 selects it based on input to an address decoding part 7. Thus, it is not necessary to change the value of the flag register 30 and to once save data of the general-purpose register even if the number of variables on the program exceeds the number of the general-purpose registers and the processing can continuously be executed. |
