| 摘要 |
PURPOSE:To reduce an operation load of a buffer of a main controller, and to simplify the constitution, by immediately storing a data which is always varied, in a back-up memory from the main controller, and storing other data only when it has been varied. CONSTITUTION:In a CPUm, a data check is executed, and if its data is an ''always varied data'', it is transferred to a buffer BFm, and thereafter, is sent out to a switching device CG, therefore, a CPUc stores a data related to a memory MMc. Unless said data is an ''always varied data'', it is transferred to the buffer when the CPUm has decided that there is a variation, is stored in the memory, and when there is no variation, transfer to the buffer and store to the memory are not executed. The quantity of a data which is always varied is much smaller than that of a data which is not always varied, the quantity of a data which must be processed simultaneously is reduced remarkably, and a constitution scale of the BFm can be simplified freely. |
