DFT - How to do scan insertion if some part of netlist is already scan inserted?

[circuitbravo]

I have a netlist which has some already scan inserted flops(not already inserted scan chains, just scan flops).

So how to do scan insertion for all by covering this already inserted scanned flops?

I'm using DFTAdvisor tool.
we use add_sub_chains to cover already inserted scan chains but how to do if you have just scan flops.

please help me.

 

[maulin sheth]

Hello,

In synopsys, I know that there is a command set_dont_touch to not convert into scan flops during compilation.

thereafter you just need to do compile -scan to convert into scan flops.
e.g.

set_dont_touch {list already_scan_converted_flops}
compile -scan

After this, you have a netlist with all flops converted into scan flops.

Thereafter, you can proceed further for scan insertion in normal way.

Thanks & Regards,
Maulin Sheth

 

[rca]

the tool does not detect that some flops are already a scan-flop?

 

[maulin sheth]

Some times, it placed a scan flop structure for flops which are already scan flops. So it is better to use set_dont_touch for those flops during compile -scan.
Thereafter, during scan configuration and setting the dft structure, do not use set_dont_touch.