[Problem] clock_gating_cell in SCAN insertion

[wjccentury]

Hello everybody !

I am doing scan insertion under 65nm using DFT Compiler XG mode. When I finished the scan insertion, I checked the dft_drc report before and after scan.
In dft_drc_before_scan.rpt:
There is a warning TEST-121 said a clock_gating_cell can't be made scannable because it is dont_touched.
In dft_drc_after_scan.rpt:
No TEST-121 warning and the test coverage is good.

Then I removed the dont_touch attribute of this clock_gating_cell, but the result was the same.

Then I checked the library information, I found the attribute of this clock_gating_cell included "b, s, d, cg", that is black_box, stable, dont_use and clock_gating_cell.

I think the reason for TEST-121 may be caused by the black_box attribute of this cell.

Am I right? I hope somebody can give ma a hand !!!

Thank you very much !!!

 

[ranga]

By default clk-gating cells are dont toch.
you need to set this as

remove _attribute dont use