multiple connected pins with the same name extracted as separate pins with _uq* suffix.

[d-m-bailey]

Version 8.3.328

On larger designs, I've noticed that pins with the same name are extracted as unique even though they are connected. This appears to be true on large designs, but I've noticed that sometimes smaller designs do not have the same problem. May be related to partitioning during extraction.

To duplicate, download the tarball,

tar zxf test_unique.tar.gz
cd test_unique
./run_ext
awk -f merge_short.awk mgmt_protect.ext/mgmt_protect.ext

merge_short.awk finds pins that are shorted via merge statements in the ext file. In this case

 "vdda1_uq0" "vdda1"
 "vssd1_uq0" "vssd1" "vssd1_uq1" "vssd1_uq2"
 "vdda2_uq0" "vdda2"
 "vssa1_uq0" "vssa1"
 "vssd2_uq0" "vssd2"
 "vccd1_uq0" "vccd1" "vccd1_uq1" "vccd1_uq2"
 "vccd2_uq0" "vccd2"
 "vssa2_uq0" "vssa2"

The extracted netlist has the following pins, where some are extracted with the _uq* suffix and some without. vssd2 appears in the above list, but is extracted correctly.

.subckt mgmt_protect caravel_clk caravel_clk2 caravel_rstn user1_vcc_powergood user1_vdd_powergood
...
+ mprj_dat_o_core[27] mprj_dat_o_core[28] vccd vccd1_uq1 vccd2_uq0 vdda1_uq0 vdda2_uq0
+ vssd vssd2 vssa1_uq0 vssa2_uq0 vssd1_uq2

It is expected that pins with the same name that are connected should not have a _uq* suffix (or at least should not appear in the netlist).

This may be merely a matter of "choosing" which of the connected ports to output in the spice file.

test_unique.tar.gz