HDL DESIGN ENTRY WITH ANNOTATED TIMING

The invention provides to the user a way of ascertaining the estimated delay through a circuit, by back-annotating the estimated delay through an instantiated macro into the HDL circuit description. Reported delays may include maximum delay, typical delay, and/or minimum delay on the critical path. Using well-known techniques for responding to textual keywords, a software procedure call is initiated whenever an HDL library macro instantiation is detected. The procedure looks up the associated timing data for the macro in a macro or device speeds file and back-annotates the data into the HDL circuit description, preferably as a comment directly following the macro instantiation. In another embodiment, the delay information is added when the file is saved. In yet another embodiment, the delay information is not added to the HDL file, but is written to a report file or displayed on the screen.