Whats the difference between functional and structural test

[akrlot]

dft question

hi;
what's the difference between functional and structural test.
thx

 

[tutx]

Re: dft question

Structure test is a testing process detects all faults of the structure of chip. For examples, stuck-at fault, coupling faults, short-circuits, crostalk, etc.
A circuit passed a structure test does not mean it will work functionally (as expected).

Functional test is a testing process verifies that the tested circuit work as its functions.

 

[akrlot]

Re: dft question

thx for reply. how these tests are made really?

 

[tutx]

Re: dft question

- Build fault model.
- Generate test pattern.
- Apply to the Circuit under test
- Read the results
- Compare with the expected.

 

[wkong_zhu]

dft question

By the way, functional test pattern also can be used as structural test.

 

[tutx]

dft question

Functional test vs Structural test:

Functional test is used when the CUT has a small number of input ports and a big number of logic stages in it. Otherwise, structural test is used.