Who can tell me the difference in set_dft_signal?

[sunspot]

set_dft_signal

Who can tell me the difference between test_point_normal_data_clock and test_point_clock for the "set_dft_signal" command used in Autofix of DFT compiler?


thanks

 

[atremp]

set_dft_signal

Description:
The set_dft_signal command lets you specify which existing primary input signals are allowed to be used for specific test purpose. In the absence of such a specification, the test point utility does not use an existing primary input port. Instead, it creates a new dedicated input port.

explain:
option test_point_normal_data_clock tell tool that we will using that clock as test clock (sometimes shared with function clock), if do not use this option, tool will generate a dedicated clock as test clock.

option test_point_clock:

By default, all test points are clocked by the new test point clock that is inserted
by default. You can use a system clock and declare it to be the test point clock
by using the set_dft_signal command.

 

[sunspot]

set_dft_signal -view

It's kind of you to help me.
But can't catch you, could you mind depicting in detail.
What is the difference between test clock and test point clock?
From the very begining of my involving in dft, I think the command create_test_clock as a declaration of test clock.
When we use these two comands, a Warning was issued as follows:
Warning: Overwriting previously specified signal on port 'CLK_PAD'. Signal type 'test_point_clock' conflicts with old type 'test_point_normal_data_source_clock'. (TESTDB-258)

thanks