Using M1.5 DC2NCF with Synopsys, the following NCF notaction is created for a create_clock command:
TIMESPEC TS_CLOCK = PERIOD : "CLOCK": 50 : HIGH : 25; NET "CLOCK" TNM = "CLOCK";
This causes the following warning in the M1.5 version of NGDBUILD:
WARNING:basts:158 - PERIOD TIMESPEC 'TS_CLOCK' has TIMEGRP 'CLOCK' which contains only PAD elements. This capability will soon be obsolete, as it has been replaced by the TNM_NET constraint.
解决方案
The constraint still works properly; however, if you wish to see these warnings disappear in NGDBUILD, you can manually change the TNM constraint to a TNM_NET constraint as following:
TIMESPEC TS_CLOCK = PERIOD : "CLOCK": 50 : HIGH : 25; NET "CLOCK" TNM_NET = "CLOCK";
The warning goes away, and the timespec will still translate properly.
This change for DC2NCF has been proposed for the next release of the software, M2.1.