Updated and corrected some of the parasitic extraction tables in
the magic techfile for sky130 (again).  This corrects issues around
the use of the "isosub" layer in conjunction with the update in magic
version 8.3.248, defining "isosub" and "dnwell" as shield types to
substrate, and defining equivalent parasitic capacitances between
all layers and "isosub" or "dnwell".

VERSION

diff --git a/VERSION b/VERSION
index 272e0b2..ac4052b 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.0.260
+1.0.261

sky130/magic/sky130.tech

diff --git a/sky130/magic/sky130.tech b/sky130/magic/sky130.tech
index 8f4ff14..9d80aea 100644
--- a/sky130/magic/sky130.tech
+++ b/sky130/magic/sky130.tech
@@ -735,7 +735,7 @@
 
 connect
   *nwell,*nsd,*mvnsd,dnwell,pnp,photo *nwell,*nsd,*mvnsd,dnwell,pnp,photo
-  pwell,*psd,*mvpsd,npn  pwell,*psd,*mvpsd,npn
+  pwell,*psd,*mvpsd,npn,isosub  pwell,*psd,*mvpsd,npn,isosub
   *li,coreli,lifill	*li,coreli,lifill
   *m1,m1fill,obsmcon	*m1,m1fill,obsmcon
 #ifdef RERAM
@@ -5209,10 +5209,13 @@
 #deep n-well
 defaultareacap     dnwell dwell 120
 
+#p-well
+defaultoverlap     pwell well dnwell dwell 120
+
 #n-well
 # NOTE:  This value not found in PEX files
 defaultareacap     nwell well 120
-defaultoverlap     nwell well dnwell dwell 0
+defaultoverlap     nwell well isosub dwell  120
 
 #n-active 
 # Rely on device models to capture *ndiff area cap
@@ -5239,6 +5242,7 @@
 
 #locali
  defaultsidewall    allli locali       33
+ defaultoverlap	    allli locali dnwell,isosub	     dwell 37
  defaultareacap     allli locali nwell,obswell,pwell well  37
  defaultperimeter   allli locali nwell,obswell,pwell well  41
  defaultoverlap     allli locali nwell,obswell,pwell well  37
@@ -5255,6 +5259,7 @@
 
 #metal1
  defaultsidewall    allm1 metal1      45
+ defaultoverlap	    allm1 metal1 dnwell,isosub	     dwell 26
  defaultareacap     allm1 metal1 nwell,obswell,pwell well  26
  defaultperimeter   allm1 metal1 nwell,obswell,pwell well  41
  defaultoverlap     allm1 metal1 nwell,obswell,pwell well  26
@@ -5280,6 +5285,7 @@
 
 #metal2
  defaultsidewall    allm2 metal2      50
+ defaultoverlap	    allm2 metal2 dnwell,isosub	     dwell 17
  defaultareacap     allm2 metal2 nwell,obswell,pwell well 17
  defaultperimeter   allm2 metal2 nwell,obswell,pwell well 38
  defaultoverlap     allm2 metal2 nwell,obswell,pwell well 17
@@ -5306,6 +5312,7 @@
 
 #metal3
  defaultsidewall    allm3 metal3     63
+ defaultoverlap	    allm3 metal3 dnwell,isosub	     dwell 12
  defaultareacap     allm3 metal3 nwell,obswell,pwell well 12
  defaultperimeter   allm3 metal3 nwell,obswell,pwell well 41
  defaultoverlap     allm3 metal3 nwell,obswell,pwell well 12
@@ -5339,6 +5346,7 @@
 #metal4
  defaultsidewall    allm4 metal4       67
 # defaultareacap     alltopm metal4 well  6
+ defaultoverlap	    allm4 metal4 dnwell,isosub	     dwell 8
  areacap     	    allm4/m4 8
  defaultperimeter   allm4 metal4 nwell,obswell,pwell well 37
  defaultoverlap     allm4 metal4 nwell,obswell,pwell well 8
@@ -5376,6 +5384,7 @@
 #metal5
  defaultsidewall    allm5 metal5       127
 # defaultareacap     allm5 metal5 well  6
+ defaultoverlap	    allm5 metal5 dnwell,isosub	     dwell 6
  areacap     	    allm5/m5 6
  defaultoverlap     allm5 metal5 nwell,obswell,pwell well  6
  defaultperimeter   allm5 metal5 nwell,obswell,pwell well  39