| 摘要 |
PURPOSE:To reduce processing load and to improve system ability by controlling with priority either of input commands stacked by a CPU and a CH by using the contents of a CPU stack ID, a channel CH stack ID and an execution cycle decision flag. CONSTITUTION:The CPU input command and the CH input command from a common bus are respectively stacked to an input command stack 16 and the stack ID at that time are also stacked to an ID stack 20 according to the commands at the same time and the stacked head stack ID are compared. Then the input command in the input command stack 16 decided based on the comparison result and the content of the execution cycle decision flag 26 is executed and the update of the flag 26 is executed to prepare for the execution of the next stacked input command. Thus even when the stacking of the CPU command are increased, the successive preferential processing of the CH command in the successive processing of the stacked CPU command becomes feasible. |
