Transition Delay Fault Methodology

[Haji-]

When using Transition Delay Fault model, there are 2 schemes:
- Launch on Capture
- Launch on Shift

When do we have to make this decision?
What do we need to consider making a selection?
Can we implement both on a given netlist?
What is the impact on test coverage by either methodology?

 

[honey13]

Hi Haji,
We can inplement both LOC and LOS on a given netlist. It depends on the commands which we are using in ATPG.

LOS will generate the basic patterns and will have high coverage.But due to transition on scan enable between launch and capture it will be difficult to meet the timing and this is less preferred.

 

[shobhit]

Hi Honey13,

Can you Plz elaborate on the STA problem we face when SE toggles, actually Iam not able to figure out the need for a new STA mode which has been created for timing closure of a legacy chip on I have started working....?


Or in other words , what special timing check is performed in STA for TFT mode which is not covered in i) Functional Mode and ii) Scan Shift Mode