摘要 |
PURPOSE:To execute at a high speed and exactly simulation executing control by processing an event in a level sort sequence, and executing a test only once only to an element for receiving a variation. CONSTITUTION:With regard to all primary input pins, a given logical value is compared with the logical value of an element table 9, and if they are different from each other, a corresponding level sort number is registered in an event stack 12, and also a logical value in the element table 9 is updated to a new logical value. Subsequently, logical operation to the corresponding element is executed by fetching the lowest level sort number, and the new logical value is compared with the old logical value. In case of coincidence, the next level sort number is fetched, but in case of dissidence, the level sort number of a think element is registered in the event stack 12, also a logical value of record in the element table 9 is updated to a new logical value, and this processing is repeated until the event stack 12 becomes empty. |