Unable to connect scan chains in rtl compiler even though there is no dft violation

[binod_kumar]

Dear All,

I am using RTL Compiler for scan synthesis.Even though i don't get any DFT violation, i am unable to connect the scan chains,I am getting following warning:

Warning : Could not connect scan chains. [DFT-415]
: No registers are available to connect into scan chains.
Mapping DFT logic introduced by scan chain connection...

Warning : Non-scan flop conversion to scan is done during incremental synthesis. The following register will not be included on a chain. [DFT-512]
: DFF_148


My tcl script is like this (without set library portion):

---

Code ActionScript - [expand]
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read_hdl s5378_net.v
elaborate  ${top_module}
set_attr dft_scan_style muxed_scan /
set_attr dft_min_number_of_scan_chains 30 ${top_module}
set_attr dft_mix_clock_edges_in_scan_chains false ${top_module}                               
define_dft scan_chain  -name chain -create_ports -non_shared_output
define_dft shift_enable -name scan_en -active high -create_port scan_sig  -default  -design   ${top_module}
synthesize -to_mapped ${top_module}
check_dft_rules  ${top_module} > dft.txt
write -mapped ${top_module} > ${top_module}_synth.v 
check_dft_rules  ${top_module}
connect_scan_chains  -auto_create_chains  ${top_module}
write_scandef ${top_module} > ${top_module}_synth1_net.def

---

Kindly help.

 

[yanshangzhao]

hi, what's the feedbck after you use "check_dft_rules" command?

 

[binod_kumar]

hi, what's the feedbck after you use "check_dft_rules" command?

hi,

i think there is no feedback in my code. i am trying to connect in automatic mode(-auto)

 

[yanshangzhao]

Can you attach the content in "dft.txt"?

 

[englishdogg]

Possibly your design is not scan mapped. Pls set the dft_scan_map_mode attribute to force_all.
This will map all flops in the design to scan mode.