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<@U017X0NM2E7>, <@U016EM8L91B> <@U0169AQ41L6>, Hi ...
# lvs
j
@Mitch Bailey, @Tim Edwards @mehdi, Hi Mitch and Tim, I just meet a problem when extracting the top_level circuit using magic, the PWR pin is missing, I also try to find if there is a short, but failed, the PEX subcircuit just as shown below. Could you help me find if there is a short in my circuit? Or if there is a bug here? Thank you very much! attach the GDS file and PEX file.
PMU_top_level.gdstop_level_pex.spice
m
@Jianwei Jia what version of magic? what rule file version? what's your extraction command? My lvs setup does not detect a power short.
Copy code
.subckt top_level clk config_in[0] config_in[1] config_in[2] config_in[3] config_in[4]
+ config_in[5] noise_D[3] noise_D[2] noise_D[1] noise_D[0] DAC_RST VREF_out D[1] D[3]
+ D[4] D[2] D[0] D[5] VOUT clk_noise non_clk_rst_n non_clk_control VPWR VGND VREF_in
+ Noise_in
@Tim Edwards Does hierarchical PEX work? I thought I remembered reading that the layout had to be flattened before parasitic extraction.
t
@Mitch Bailey: In this case the netlist is extracted with capacitance parasitics only; that works fine hierarchically. It's only when doing full R-C extraction that the netlist needs to be flattened, because of all the issues around nets being broken into resistive segments.
👍 1
j
@Mitch Bailey, Hi Mitch, the version of my magic is 8.3.271, and the sky130A.tech version is 1.0.255-0-g476f742, the extract command is: magic -rcfile ./sky130A/sky130A.magicrc -noconsole -dnull << EOF gds read $1 load $2 extract all ext2spice lvs ext2spice -o ./EXTRACT_CDL/$2_lvsmag.spice extract all ext2spice lvs ext2spice cthresh 0 ext2spice -o ./EXTRACT_PEX/$2_pex.spice Thank you very much!
m
I used 
Magic 8.3 revision 315
and rule file 
1.0.291-20-g05af1d0
Does your 
lvsmag.spice
also drop the 
VPWR
net?
j
oh, let me try to update my version, yeah, in my lvsmag.spice, the VPWR is also missing.
@Mitch Bailey, Hi Mitch, currently I have extracted a PEX file with C, but when I want to flatten the GDS to extract a PEX with R and C, I meet some problems, when I use the command: flatten -dotoplabels, I get a PEX file with too many pins (including top_level pin labels and some subcircuit pin labels), how can I flatten a GDS file which only keeps the top_level pin labels and extract a PEX file with R and C properly? I also use the ext2spice rthresh 0 ext2spice cthresh 0 to extract the R but it seems doesn't work. Attach the GDS file, Flattened GDS file, and extracted lvsmag file with too many pin labels, Thank you very much!
PMU_top_level.gdstop_level_lvsmag.spice
m
What are all the magic commands that you're using?
j
Hi Mitch, for the flatten the gds, the command is: magic -rcfile ./sky130A/sky130A.magicrc -noconsole -dnull << EOF gds read $1 load $2 flatten -dotoplabels $2_flat load $2_flat gds write ./FLATTEN_GDS/$2_flat.gds EOF For the extract lvsmag and PEX command: magic -rcfile ./sky130A/sky130A.magicrc -noconsole -dnull << EOF gds read ./FLATTEN_GDS/$2.gds load $2 extract all ext2spice lvs ext2spice -o ./EXTRACT_CDL/$2_lvsmag.spice extract all ext2spice lvs ext2spice rthresh 0 ext2spice cthresh 0 ext2spice -o ./EXTRACT_PEX/$2_pex.spice exit EOF
t
@Jianwei Jia: What you're doing is not full R-C extraction. You would want to do this:
Copy code
magic -rcfile ./sky130A/sky130A.magicrc -noconsole -dnull << EOF
gds read ./FLATTEN_GDS/$2.gds
load $2
extract do local
extract all
ext2sim labels on
ext2sim
extresist tolerance 10
extresist
ext2spice lvs
ext2spice cthresh 0
ext2spice extresist on
ext2spice -o ./EXTRACT_PEX/$2_pex.spice
quit -noprompt
EOF
Do not use the flattened netlist to generate netlist output for LVS, as it just makes interpreting the LVS results a lot harder.
j
@Tim Edwards, Thank you very much, Tim! Let me try it.
@Tim Edwards, Hi Tim, I have used this command to run the extraction, but I don't see any R extracted, is it right? Attach my extracting PEX file using the above command. Thank you very much!
top_level_pex.spice
@Mitch Bailey, Hi Mitch, when I use the command below to extract the RC PEX file, I meet a problem, it seems that it can't recognize my .sim file? I'm a little confused. And the PEX file also doesn't include the R, just C.
m
@Tim Edwards? I don't have much experience with PEX.
m
which version of magic are you using @Jianwei Jia
j
My magic version is 8.3.315 and my PDK version is 1.0.310-24-g92ec69e
m
so maybe you should move your question to the magic channel so @Tim Edwards can help
j
OK
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