| 摘要 |
PURPOSE:To attain selective loading of a microprogram at an optional time point by giving priorities to microprogram store request signals and storing the microprogram to a data processor having the priority. CONSTITUTION:The microprogram muP store request signal of a data processor 1 is set at logic 1, and a priority circuit 15 gives the priority to the processor 1. Thus a muP store indication signal 111 is set at 1 with other store indication signals 112-114 kept at 0 respectively. When the signal 111 is set at 1, the output of an OR circuit 20 is also set at 1. Then the muP and the store control signal which is stored in a nonvolatile memory in a holding control circuit 30 are outputted to a common data path 40. The data on the path 40 is not transmitted through data paths 62-64 owing to permission circuits 52-54 since signals 112- 114 are set at 0. While the data on the path 40 passes through a path 61 via a permissiin circuit 51 since the signal 111 is kept at 1. In other words, only the path 61 can output both the muP and the store control signal to the processor 1. Thus the muP can be loaded on the processor 1.
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