| 摘要 |
PURPOSE: To input the timing specification information of a digital device by the format of natural language by providing a mark specification description language which can be easily interpreted, and which can be exactly executed without any ambiguity by a computer. CONSTITUTION: The information of a specification and dependence based on the description of the timing constraint condition of a user is set. The user inputs specification characteristic information by indicating relation between signals. For example, a timing constraint t4 -t6 is designated as 'from a set-up time B high to a clock A low'. The user indicates the minimum expression of 10 nano seconds in response to the designation. In this case, the set of the information is related signals (A and B) and the type (set-up time) of a timing constraint. The signal A is a clock signal and the signal B is a logical level 1 at the beginning of the specification, the signal A is the logical level 0 at the end of the specification, and the minimum expression (10 nano seconds) is designated. |
