Simple update to add a script that adds the isolated substrate

layer to two cells that need it for passing LVS.

scripts/add_isosub_layers.sh

@@ -0,0 +1,53 @@
+#!/bin/sh
+#
+#-------------------------------------------------------------------
+# add_isosub_layers.sh --
+#
+# This script adds isolated substrate layers to two circuits
+# gpio_control_block and mgmt_protect that require it.
+#
+# This annotation is easy to do by hand.  However, the script
+# formalizes the procedure and serves as a reminder that it needs
+# to be done because the synthesis tools have no way to understand
+# when the substrate has implied separate regions, or what to do
+# about it.  Without the isolated substrate region markers, the
+# layout extraction will merge the ground domains and the design
+# will fail LVS.
+#
+# NOTE:  This script is specific to the existing caravel chip
+# layout for MPW-7.  If either block is resynthesized, the positions
+# of the isolated ground areas need to be determined and this script
+# needs to be updated to match.
+#
+# Written by Tim Edwards for MPW-7  10/17/2022
+#-------------------------------------------------------------------
+
+echo ${PDK_ROOT:=/usr/share/pdk} > /dev/null
+echo ${PDK:=sky130A} > /dev/null
+
+echo "Annotating gpio_control_block layout with isolated substrate"
+magic -dnull -noconsole -rcfile ${PDK_ROOT}/${PDK}/libs.tech/magic/${PDK}.magicrc << EOF
+drc off
+snap internal
+load gpio_control_block
+tech unlock *
+box values 1096 1592 2678 4514
+paint isosub
+writeall force gpio_control_block
+quit -noprompt
+EOF
+
+echo "Annotating mgmt_protect layout with isolated substrate"
+magic -dnull -noconsole -rcfile ${PDK_ROOT}/${PDK}/libs.tech/magic/${PDK}.magicrc << EOF
+drc off
+snap internal
+load mgmt_protect
+tech unlock *
+box values 65700 6898 86564 9130
+paint isosub
+box values 136230 10086 205344 13664
+paint isosub
+writeall force mgmt_protect
+quit -noprompt
+EOF
+