Fix the simple_por to (logically) isolate the 1.8V and 3.3V grounds. (#…

…90)

* Fix the simple_por to (logically) isolate the 1.8V and 3.3V grounds.
This commit does the following:
(1) Corrects the xschem simple_por schematic to separate the 1.8V and 3.3V grounds.
(2) Corrects the xschem simple_por symbol to separate the 1.8V and 3.3V grounds.
(3) Corrects the xschem testbench to connect to both grounds of simple_por.
(4) Corrects the simple_por layout to remove the 1.8V logic from the
    3.3V ground and connect it instead to the 1.8V ground.
(5) Extends the top-level power routing of caravel and caravan to
    make a better connection to the simple_por 1.8V ground.
(6) Adds an LVS script to properly check the simple_por layout against the
    xschem-generated schematic netlist.

NOTE: None of these modifications change the function of any circuit.  The
1.8V and 3.3V ground nets are only logically separated in the netlists but
share the substrate.  This fix cleanly defines the 1.8V and 3.3V grounds
within the simple_por, where they were previously mingled.  It also ensures
that the full LVS for caravel and caravan can now include the simple_por at
the transistor level and still pass.

* Updated the GDS of simple_por (previously did not remove GDS_FILE
from the .mag file and so it just overwrote the original GDS file
with itself).

* Corrected a route to simple_por in the top level of both caravel
and caravan that was shorting to the extra metals put on top of
the substrate contact across the top (bottom, in the top level)
of the simple_por layout.

mag/caravan.mag

@@ -1,7 +1,7 @@
 magic
 tech sky130A
 magscale 1 2
-timestamp 1650895425
+timestamp 1651019166
 << viali >>
 rect 658360 47209 658394 47243
 << metal1 >>
@@ -18486,11 +18486,11 @@ rect 575658 43120 575664 43132
 rect 575716 43120 575722 43172
 rect 223574 43052 223580 43104
 rect 223632 43092 223638 43104
-rect 661034 43092 661040 43104
-rect 223632 43064 661040 43092
+rect 661454 43092 661460 43104
+rect 223632 43064 661460 43092
 rect 223632 43052 223638 43064
-rect 661034 43052 661040 43064
-rect 661092 43052 661098 43104
+rect 661454 43052 661460 43064
+rect 661512 43052 661518 43104
 rect 475470 42616 475476 42628
 rect 474490 42588 475476 42616
 rect 475470 42576 475476 42588
@@ -23772,7 +23772,7 @@ rect 365168 44072 365220 44124
 rect 390192 43120 390244 43172
 rect 575664 43120 575716 43172
 rect 223580 43052 223632 43104
-rect 661040 43052 661092 43104
+rect 661460 43052 661512 43104
 rect 475476 42576 475528 42628
 rect 513288 41964 513340 42016
 rect 518532 41964 518584 42016
@@ -44442,11 +44442,13 @@ rect 661040 47388 661092 47394
 rect 661040 47330 661092 47336
 rect 650000 46980 650052 46986
 rect 650000 46922 650052 46928
+rect 661052 46912 661080 47330
+rect 661052 46884 661500 46912
 rect 610348 45824 610400 45830
 rect 610348 45766 610400 45772
-rect 661052 43110 661080 47330
-rect 661040 43104 661092 43110
-rect 661040 43046 661092 43052
+rect 661472 43110 661500 46884
+rect 661460 43104 661512 43110
+rect 661460 43046 661512 43052
 rect 610256 41404 610308 41410
 rect 610256 41346 610308 41352
 rect 575756 41336 575808 41342
@@ -58907,7 +58909,7 @@ timestamp 1637698689
 transform 1 0 -53810 0 1 -20
 box 367960 10204 399802 14768
 use caravan_power_routing  caravan_power_routing_0
-timestamp 1638483672
+timestamp 1650915033
 transform 1 0 0 0 1 0
 box 0 0 717600 1037600
 use caravan_signal_routing  caravan_signal_routing_0
@@ -58923,111 +58925,111 @@ timestamp 1649951985
 transform 1 0 149318 0 1 16066
 box -262 -10162 35048 2764
 use gpio_control_block  gpio_control_bidir_1\[0\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 121000
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_bidir_1\[1\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 166200
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_bidir_2\[0\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 289000
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_bidir_2\[1\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 245800
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_bidir_2\[2\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 202600
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1\[0\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 523800
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1\[1\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 568800
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1\[2\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 614000
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1\[3\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 659000
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1\[4\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 704200
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1\[5\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 884800
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1a\[0\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 211200
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1a\[1\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 256400
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1a\[2\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 301400
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1a\[3\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 346400
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1a\[4\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 391600
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_1a\[5\]
-timestamp 1650313688
+timestamp 1650900217
 transform -1 0 710203 0 1 479800
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[0\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 805400
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[1\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 762200
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[2\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 719000
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[3\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 675800
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[4\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 632600
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[5\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 589400
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[6\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 546200
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[7\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 418600
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[8\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 375400
 box 882 416 34000 13000
 use gpio_control_block  gpio_control_in_2\[9\]
-timestamp 1650313688
+timestamp 1650900217
 transform 1 0 7631 0 1 332200
 box 882 416 34000 13000
 use gpio_defaults_block_1803 gpio_defaults_block_0\[0\]
@@ -59163,7 +59165,7 @@ timestamp 1638875307
 transform 1 0 628146 0 1 80944
 box 0 0 15000 15000
 use simple_por  por
-timestamp 1638031832
+timestamp 1650914729
 transform 1 0 650146 0 -1 55282
 box -52 -62 11344 8684
 use xres_buf  rstb_level