Added new pad types for use in the caravel and caravan chips for the user 1.8V voltage domains; these pads have clamp connections but do not connect to the pad ring, and rely on the power supply being routed inside the chip core.

diff --git a/sky130/custom/sky130_fd_io/cdl/sky130_ef_io.cdl b/sky130/custom/sky130_fd_io/cdl/sky130_ef_io.cdl
index d1045f7..af6f5d5 100644
--- a/sky130/custom/sky130_fd_io/cdl/sky130_ef_io.cdl
+++ b/sky130/custom/sky130_fd_io/cdl/sky130_ef_io.cdl

@@ -528,6 +528,50 @@
 .ENDS
 
 *--------------------------------------------------------------------------
+* sky130_ef_io__vccd_lvc_clamped3_pad
+* sky130_ef_io__vccd_lvc_pad with pad and LV clamp positive connection to
+* VCCD1, clamp negative connection to VSSD1, and and back-to-back diodes
+* connecting VSSIO to VSSD1
+*--------------------------------------------------------------------------
+
+.SUBCKT sky130_ef_io__vccd_lvc_clamped3_pad
++ AMUXBUS_A AMUXBUS_B VCCD_PAD
++ VSSA VDDA VSWITCH VDDIO_Q VCCHIB VDDIO VCCD
++ VSSIO VSSD VSSIO_Q VCCD1 VSSD1
+
+* Instantiate the underlying power pad (connects P_PAD to VCCD)
+Xsky130_fd_io__top_power_lvc_base
++ AMUXBUS_A AMUXBUS_B VSSD1 VCCD1 VCCD1 VDDIO
++ VCCD1 VCCD_PAD
++ VSSIO VSSD1 VCCD VCCHIB VDDA VDDIO VDDIO_Q
++ VSSA VSSD VSSIO VSSIO_Q VSWITCH
++ sky130_fd_io__top_power_lvc_wpad
+
+.ENDS
+
+*--------------------------------------------------------------------------
+* sky130_ef_io__vssd_lvc_clamped3_pad
+* sky130_ef_io__vssd_lvc_pad with pad and LV clamp negative connection to
+* VSSD1, clamp positive connection to VCCD1, and back-to-back diodes
+* connecting VSSIO to VSSD1
+*--------------------------------------------------------------------------
+
+.SUBCKT sky130_ef_io__vssd_lvc_clamped3_pad
++ AMUXBUS_A AMUXBUS_B VSSD_PAD
++ VSSA VDDA VSWITCH VDDIO_Q VCCHIB VDDIO VCCD
++ VSSIO VSSD VSSIO_Q VCCD1 VSSD1
+
+* Instantiate the underlying ground pad (connects G_PAD to VSSD)
+Xsky130_fd_io__top_ground_lvc_base
++ AMUXBUS_A AMUXBUS_B VSSIO VCCD1 VCCD1
++ VSSD1 VSSD_PAD
++ VDDIO VSSIO VSSD VCCD VCCHIB VDDA VDDIO VDDIO_Q
++ VSSA VSSD VSSIO VSSIO_Q VSWITCH
++ sky130_fd_io__top_ground_lvc_wpad
+
+.ENDS
+
+*--------------------------------------------------------------------------
 * sky130_ef_io__vccd_lvc_clamped_pad
 * sky130_ef_io__vccd_lvc_pad with LV clamp connections to VCCD and VSSD,
 * and back-to-back diodes connecting VSSD to VSSIO

diff --git a/sky130/custom/sky130_fd_io/gds/sky130_ef_io.gds b/sky130/custom/sky130_fd_io/gds/sky130_ef_io.gds
index 52a905f..1b3c57a 100644
--- a/sky130/custom/sky130_fd_io/gds/sky130_ef_io.gds
+++ b/sky130/custom/sky130_fd_io/gds/sky130_ef_io.gds
Binary files differ

diff --git a/sky130/custom/sky130_fd_io/lef/sky130_ef_io__vccd_lvc_clamped3_pad.lef b/sky130/custom/sky130_fd_io/lef/sky130_ef_io__vccd_lvc_clamped3_pad.lef
new file mode 100644
index 0000000..a72c379
--- /dev/null
+++ b/sky130/custom/sky130_fd_io/lef/sky130_ef_io__vccd_lvc_clamped3_pad.lef

@@ -0,0 +1,379 @@
+VERSION 5.7 ;
+  NOWIREEXTENSIONATPIN ON ;
+  DIVIDERCHAR "/" ;
+  BUSBITCHARS "[]" ;
+MACRO sky130_ef_io__vccd_lvc_clamped3_pad
+  CLASS PAD POWER ;
+  FOREIGN sky130_ef_io__vccd_lvc_clamped3_pad ;
+  ORIGIN 0.000 0.000 ;
+  SIZE 75.000 BY 197.965 ;
+  PIN AMUXBUS_A
+    DIRECTION INOUT ;
+    USE SIGNAL ;
+    PORT
+      LAYER met4 ;
+        RECT 0.000 51.090 75.000 54.070 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 51.090 1.270 54.070 ;
+    END
+  END AMUXBUS_A
+  PIN AMUXBUS_B
+    DIRECTION INOUT ;
+    USE SIGNAL ;
+    PORT
+      LAYER met4 ;
+        RECT 0.000 46.330 75.000 49.310 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 46.330 1.270 49.310 ;
+    END
+  END AMUXBUS_B
+  PIN VCCD_PAD
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 10.270 99.865 64.670 167.130 ;
+    END
+  END VCCD_PAD
+  PIN VSSA
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 45.700 75.000 54.700 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 73.730 34.805 75.000 38.050 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 45.700 1.270 54.700 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 34.805 1.270 38.050 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 49.610 75.000 50.790 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 54.370 75.000 54.700 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 45.700 75.000 46.030 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 34.700 75.000 38.150 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 45.700 1.270 46.030 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 49.610 1.270 50.790 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 54.370 1.270 54.700 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 34.700 1.270 38.150 ;
+    END
+  END VSSA
+  PIN VDDA
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 74.035 13.000 75.000 16.250 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 13.000 0.965 16.250 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 74.035 12.900 75.000 16.350 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 12.900 0.965 16.350 ;
+    END
+  END VDDA
+  PIN VSWITCH
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 29.950 75.000 33.200 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 29.950 1.270 33.200 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 29.850 75.000 33.300 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 29.850 1.270 33.300 ;
+    END
+  END VSWITCH
+  PIN VDDIO_Q
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 62.150 75.000 66.400 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 62.150 1.270 66.400 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 62.050 75.000 66.500 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 62.050 1.270 66.500 ;
+    END
+  END VDDIO_Q
+  PIN VDDIO
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 68.000 75.000 92.950 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 73.730 17.850 75.000 22.300 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 68.000 1.270 92.950 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 17.850 1.270 22.300 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 17.750 75.000 22.400 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 68.000 75.000 92.965 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 17.750 1.270 22.400 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 68.000 1.270 92.965 ;
+    END
+  END VDDIO
+  PIN VCCD
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 6.950 75.000 11.400 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 6.950 1.270 11.400 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 6.850 75.000 11.500 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 6.850 1.270 11.500 ;
+    END
+  END VCCD
+  PIN VSSIO
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met4 ;
+        RECT 74.225 173.750 76.470 197.965 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 173.750 1.205 197.965 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 73.730 23.900 75.000 28.350 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 23.900 1.270 28.350 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 23.800 75.000 28.450 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 173.750 75.000 197.965 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 173.750 1.270 197.965 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 23.800 1.270 28.450 ;
+    END
+  END VSSIO
+  PIN VSSD
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 39.650 75.000 44.100 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 39.650 1.270 44.100 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 39.550 75.000 44.200 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 39.550 1.270 44.200 ;
+    END
+  END VSSD
+  PIN VSSIO_Q
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 56.300 75.000 60.550 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 56.300 1.270 60.550 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 56.200 75.000 60.650 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 56.200 1.270 60.650 ;
+    END
+  END VSSIO_Q
+  PIN VCCD1
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met3 ;
+        RECT 0.500 -7.830 24.500 47.345 ;
+    END
+    PORT
+      LAYER met3 ;
+        RECT 50.755 -7.710 74.700 84.430 ;
+    END
+  END VCCD1
+  PIN VSSD1
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met3 ;
+        RECT 25.950 -7.530 49.260 -2.510 ;
+    END
+  END VSSD1
+  OBS
+      LAYER li1 ;
+        RECT 0.240 0.985 74.755 197.745 ;
+      LAYER met1 ;
+        RECT 0.120 0.000 75.000 197.805 ;
+        RECT 16.655 -0.035 56.565 0.000 ;
+        RECT 20.925 -0.780 56.565 -0.035 ;
+        RECT 76.200 -0.780 85.935 75.385 ;
+        RECT 20.925 -6.885 85.935 -0.780 ;
+        RECT 20.925 -10.885 81.935 -6.885 ;
+        POLYGON 81.935 -6.885 85.935 -6.885 81.935 -10.885 ;
+      LAYER met2 ;
+        RECT 0.490 0.000 75.000 197.965 ;
+        RECT 76.200 23.425 85.935 197.965 ;
+        RECT 0.490 -2.510 20.495 0.000 ;
+        RECT 20.925 -0.035 53.535 0.000 ;
+        POLYGON 20.495 -1.510 21.495 -2.510 20.495 -2.510 ;
+        POLYGON 54.095 -1.510 54.095 -2.510 53.095 -2.510 ;
+        RECT 54.095 -2.510 74.700 0.000 ;
+        RECT 0.490 -2.560 74.700 -2.510 ;
+        POLYGON 0.490 -2.560 5.490 -2.560 5.490 -7.560 ;
+        RECT 5.490 -7.560 69.700 -2.560 ;
+        POLYGON 69.700 -2.560 74.700 -2.560 69.700 -7.560 ;
+      LAYER met3 ;
+        RECT 0.490 84.830 75.000 197.965 ;
+        RECT 76.200 173.750 85.935 197.965 ;
+        RECT 0.490 47.745 50.355 84.830 ;
+        RECT 0.490 -7.830 0.500 4.310 ;
+        RECT 24.900 0.000 50.355 47.745 ;
+        RECT 76.200 23.800 85.935 28.450 ;
+        RECT 26.000 -0.035 36.880 0.000 ;
+        RECT 38.380 -0.035 49.255 0.000 ;
+      LAYER met4 ;
+        RECT 1.670 173.350 73.330 197.965 ;
+        RECT 76.470 173.750 85.935 197.965 ;
+        RECT 0.000 93.365 75.000 173.350 ;
+        RECT 1.670 67.600 73.330 93.365 ;
+        RECT 0.000 66.900 75.000 67.600 ;
+        RECT 1.670 61.650 73.330 66.900 ;
+        RECT 0.000 61.050 75.000 61.650 ;
+        RECT 1.670 55.800 73.330 61.050 ;
+        RECT 0.000 55.100 75.000 55.800 ;
+        RECT 1.670 49.710 73.330 50.690 ;
+        RECT 0.000 44.600 75.000 45.300 ;
+        RECT 1.670 39.150 73.330 44.600 ;
+        RECT 0.000 38.550 75.000 39.150 ;
+        RECT 1.670 34.300 73.330 38.550 ;
+        RECT 0.000 33.700 75.000 34.300 ;
+        RECT 1.670 29.450 73.330 33.700 ;
+        RECT 0.000 28.850 75.000 29.450 ;
+        RECT 1.670 23.400 73.330 28.850 ;
+        RECT 75.000 23.800 85.935 28.450 ;
+        RECT 0.000 22.800 75.000 23.400 ;
+        RECT 1.670 17.350 73.330 22.800 ;
+        RECT 0.000 16.750 75.000 17.350 ;
+        RECT 1.365 12.500 73.635 16.750 ;
+        RECT 0.000 11.900 75.000 12.500 ;
+        RECT 1.670 6.450 73.330 11.900 ;
+        RECT 0.000 0.000 75.000 6.450 ;
+      LAYER met5 ;
+        RECT 0.000 168.730 75.000 197.965 ;
+        RECT 0.000 98.265 8.670 168.730 ;
+        RECT 66.270 98.265 75.000 168.730 ;
+        RECT 0.000 94.550 75.000 98.265 ;
+        RECT 2.870 34.805 72.130 94.550 ;
+        RECT 0.000 34.800 75.000 34.805 ;
+        RECT 2.870 16.250 72.130 34.800 ;
+        RECT 2.565 13.000 72.435 16.250 ;
+        RECT 2.870 5.350 72.130 13.000 ;
+        RECT 0.000 0.100 75.000 5.350 ;
+  END
+END sky130_ef_io__vccd_lvc_clamped3_pad
+END LIBRARY
+

diff --git a/sky130/custom/sky130_fd_io/lef/sky130_ef_io__vssd_lvc_clamped3_pad.lef b/sky130/custom/sky130_fd_io/lef/sky130_ef_io__vssd_lvc_clamped3_pad.lef
new file mode 100644
index 0000000..3c4dc69
--- /dev/null
+++ b/sky130/custom/sky130_fd_io/lef/sky130_ef_io__vssd_lvc_clamped3_pad.lef

@@ -0,0 +1,372 @@
+VERSION 5.7 ;
+  NOWIREEXTENSIONATPIN ON ;
+  DIVIDERCHAR "/" ;
+  BUSBITCHARS "[]" ;
+MACRO sky130_ef_io__vssd_lvc_clamped3_pad
+  CLASS PAD POWER ;
+  FOREIGN sky130_ef_io__vssd_lvc_clamped3_pad ;
+  ORIGIN 0.000 0.000 ;
+  SIZE 75.000 BY 197.965 ;
+  PIN AMUXBUS_A
+    DIRECTION INOUT ;
+    USE SIGNAL ;
+    PORT
+      LAYER met4 ;
+        RECT 0.000 51.090 75.000 54.070 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 51.090 1.270 54.070 ;
+    END
+  END AMUXBUS_A
+  PIN AMUXBUS_B
+    DIRECTION INOUT ;
+    USE SIGNAL ;
+    PORT
+      LAYER met4 ;
+        RECT 0.000 46.330 75.000 49.310 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 46.330 1.270 49.310 ;
+    END
+  END AMUXBUS_B
+  PIN VSSD_PAD
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met5 ;
+        RECT 10.270 99.865 64.670 167.130 ;
+    END
+  END VSSD_PAD
+  PIN VSSA
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 45.700 75.000 54.700 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 73.730 34.805 75.000 38.050 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 45.700 1.270 54.700 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 34.805 1.270 38.050 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 49.610 75.000 50.790 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 54.370 75.000 54.700 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 45.700 75.000 46.030 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 34.700 75.000 38.150 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 45.700 1.270 46.030 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 49.610 1.270 50.790 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 54.370 1.270 54.700 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 34.700 1.270 38.150 ;
+    END
+  END VSSA
+  PIN VDDA
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 74.035 13.000 75.000 16.250 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 13.000 0.965 16.250 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 74.035 12.900 75.000 16.350 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 12.900 0.965 16.350 ;
+    END
+  END VDDA
+  PIN VSWITCH
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 29.950 75.000 33.200 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 29.950 1.270 33.200 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 29.850 75.000 33.300 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 29.850 1.270 33.300 ;
+    END
+  END VSWITCH
+  PIN VDDIO_Q
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 62.150 75.000 66.400 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 62.150 1.270 66.400 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 62.050 75.000 66.500 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 62.050 1.270 66.500 ;
+    END
+  END VDDIO_Q
+  PIN VDDIO
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 68.000 75.000 92.950 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 73.730 17.850 75.000 22.300 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 68.000 1.270 92.950 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 17.850 1.270 22.300 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 17.750 75.000 22.400 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 68.000 75.000 92.965 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 17.750 1.270 22.400 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 68.000 1.270 92.965 ;
+    END
+  END VDDIO
+  PIN VCCD
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 6.950 75.000 11.400 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 6.950 1.270 11.400 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 6.850 75.000 11.500 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 6.850 1.270 11.500 ;
+    END
+  END VCCD
+  PIN VSSIO
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met4 ;
+        RECT 74.225 173.750 76.470 197.965 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 173.750 1.205 197.965 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 73.730 23.900 75.000 28.350 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 23.900 1.270 28.350 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 23.800 75.000 28.450 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 173.750 75.000 197.965 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 173.750 1.270 197.965 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 23.800 1.270 28.450 ;
+    END
+  END VSSIO
+  PIN VSSD
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 39.650 75.000 44.100 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 39.650 1.270 44.100 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 39.550 75.000 44.200 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 39.550 1.270 44.200 ;
+    END
+  END VSSD
+  PIN VSSIO_Q
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met5 ;
+        RECT 73.730 56.300 75.000 60.550 ;
+    END
+    PORT
+      LAYER met5 ;
+        RECT 0.000 56.300 1.270 60.550 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 73.730 56.200 75.000 60.650 ;
+    END
+    PORT
+      LAYER met4 ;
+        RECT 0.000 56.200 1.270 60.650 ;
+    END
+  END VSSIO_Q
+  PIN VSSD1
+    DIRECTION INOUT ;
+    USE GROUND ;
+    PORT
+      LAYER met3 ;
+        RECT 0.500 -9.480 24.500 26.400 ;
+    END
+    PORT
+      LAYER met3 ;
+        RECT 50.755 -9.510 74.700 27.120 ;
+    END
+  END VSSD1
+  PIN VCCD1
+    DIRECTION INOUT ;
+    USE POWER ;
+    PORT
+      LAYER met3 ;
+        RECT 26.000 -9.490 49.255 -2.290 ;
+    END
+  END VCCD1
+  OBS
+      LAYER li1 ;
+        RECT 0.240 0.985 74.755 197.745 ;
+      LAYER met1 ;
+        RECT 0.120 0.000 75.000 197.805 ;
+        RECT 16.655 -0.035 56.565 0.000 ;
+        RECT 20.925 -0.780 56.565 -0.035 ;
+        RECT 76.200 -0.780 85.935 75.385 ;
+        RECT 20.925 -6.885 85.935 -0.780 ;
+        RECT 20.925 -10.885 81.935 -6.885 ;
+        POLYGON 81.935 -6.885 85.935 -6.885 81.935 -10.885 ;
+      LAYER met2 ;
+        RECT 0.500 0.000 75.000 197.965 ;
+        RECT 76.200 23.425 85.935 197.965 ;
+        RECT 0.500 -0.035 20.495 0.000 ;
+        RECT 20.925 -0.035 53.535 0.000 ;
+        RECT 54.095 -0.035 74.700 0.000 ;
+      LAYER met3 ;
+        RECT 0.500 27.520 75.000 197.965 ;
+        RECT 76.200 173.750 85.935 197.965 ;
+        RECT 0.500 26.800 50.355 27.520 ;
+        RECT 24.900 0.000 50.355 26.800 ;
+        RECT 76.200 23.800 85.935 28.450 ;
+        RECT 26.000 -2.290 36.880 0.000 ;
+        RECT 38.380 -2.290 49.255 0.000 ;
+      LAYER met4 ;
+        RECT 1.670 173.350 73.330 197.965 ;
+        RECT 76.470 173.750 85.935 197.965 ;
+        RECT 0.000 93.365 75.000 173.350 ;
+        RECT 1.670 67.600 73.330 93.365 ;
+        RECT 0.000 66.900 75.000 67.600 ;
+        RECT 1.670 61.650 73.330 66.900 ;
+        RECT 0.000 61.050 75.000 61.650 ;
+        RECT 1.670 55.800 73.330 61.050 ;
+        RECT 0.000 55.100 75.000 55.800 ;
+        RECT 1.670 49.710 73.330 50.690 ;
+        RECT 0.000 44.600 75.000 45.300 ;
+        RECT 1.670 39.150 73.330 44.600 ;
+        RECT 0.000 38.550 75.000 39.150 ;
+        RECT 1.670 34.300 73.330 38.550 ;
+        RECT 0.000 33.700 75.000 34.300 ;
+        RECT 1.670 29.450 73.330 33.700 ;
+        RECT 0.000 28.850 75.000 29.450 ;
+        RECT 1.670 23.400 73.330 28.850 ;
+        RECT 75.000 23.800 85.935 28.450 ;
+        RECT 0.000 22.800 75.000 23.400 ;
+        RECT 1.670 17.350 73.330 22.800 ;
+        RECT 0.000 16.750 75.000 17.350 ;
+        RECT 1.365 12.500 73.635 16.750 ;
+        RECT 0.000 11.900 75.000 12.500 ;
+        RECT 1.670 6.450 73.330 11.900 ;
+        RECT 0.000 0.000 75.000 6.450 ;
+      LAYER met5 ;
+        RECT 0.000 168.730 75.000 197.965 ;
+        RECT 0.000 98.265 8.670 168.730 ;
+        RECT 66.270 98.265 75.000 168.730 ;
+        RECT 0.000 94.550 75.000 98.265 ;
+        RECT 2.870 34.805 72.130 94.550 ;
+        RECT 0.000 34.800 75.000 34.805 ;
+        RECT 2.870 16.250 72.130 34.800 ;
+        RECT 2.565 13.000 72.435 16.250 ;
+        RECT 2.870 5.350 72.130 13.000 ;
+        RECT 0.000 0.100 75.000 5.350 ;
+  END
+END sky130_ef_io__vssd_lvc_clamped3_pad
+END LIBRARY
+

diff --git a/sky130/custom/sky130_fd_io/mag/sky130_ef_io__vccd_lvc_clamped3_pad.mag b/sky130/custom/sky130_fd_io/mag/sky130_ef_io__vccd_lvc_clamped3_pad.mag
new file mode 100644
index 0000000..aa306ec
--- /dev/null
+++ b/sky130/custom/sky130_fd_io/mag/sky130_ef_io__vccd_lvc_clamped3_pad.mag

@@ -0,0 +1,251 @@
+magic
+tech sky130A
+magscale 1 2
+timestamp 1636574685
+<< checkpaint >>
+rect 1196 59270 3717 61791
+rect 2925 40853 18455 40854
+rect -1260 40846 18455 40853
+rect -3455 38669 18488 40846
+rect -5650 10928 18488 38669
+rect -5650 10286 18674 10928
+rect -5650 6546 19310 10286
+rect -5650 5974 18674 6546
+rect -5650 -3444 18488 5974
+rect -5650 -5621 16293 -3444
+<< metal1 >>
+rect 6867 95 7067 195
+rect 5242 -7 5540 69
+<< metal2 >>
+rect 98 -502 4099 287
+rect 10953 62 14940 715
+rect 6888 -7 8888 58
+tri 4099 -502 4299 -302 sw
+tri 10619 -502 10819 -302 se
+rect 10819 -502 14940 62
+rect 98 -512 14940 -502
+tri 98 -1512 1098 -512 ne
+rect 1098 -564 13940 -512
+rect 1098 -1456 5250 -564
+rect 9804 -1456 13940 -564
+rect 1098 -1512 13940 -1456
+tri 13940 -1512 14940 -512 nw
+<< via2 >>
+rect 5250 -1456 9804 -564
+<< metal3 >>
+rect 4790 6390 5306 11272
+rect 9812 6460 10328 11342
+rect 98 -1566 4900 862
+rect 5200 -7 7374 918
+rect 7676 -7 9850 918
+rect 5190 -564 9852 -502
+rect 5190 -1456 5250 -564
+rect 9804 -1456 9852 -564
+rect 5190 -1506 9852 -1456
+rect 10151 -1542 14940 862
+<< metal4 >>
+rect 0 34750 254 39593
+rect 14746 34750 15000 39593
+rect 0 13600 254 18593
+rect 14746 13600 15000 18593
+rect 0 12410 254 13300
+rect 14746 12410 15000 13300
+rect 0 11240 254 12130
+rect 14746 11240 15000 12130
+rect 0 10874 254 10940
+rect 14746 10874 15000 10940
+rect 0 10218 100 10814
+rect 14746 10218 14846 10814
+rect 0 9922 254 10158
+rect 14746 9922 15000 10158
+rect 0 9266 116 9862
+rect 14746 9266 14862 9862
+rect 0 9140 254 9206
+rect 14746 9140 15000 9206
+rect 0 7910 254 8840
+rect 14746 7910 15000 8840
+rect 0 6940 254 7630
+rect 14746 6940 15000 7630
+rect 0 5970 254 6660
+rect 14746 5970 15000 6660
+rect 0 4760 254 5690
+rect 14746 4760 15000 5690
+rect 0 3550 254 4480
+rect 14746 3550 15000 4480
+rect 0 2580 254 3270
+rect 14746 2580 15000 3270
+rect 0 1370 254 2300
+rect 14746 1370 15000 2300
+rect 0 0 254 1090
+rect 14746 0 15000 1090
+<< metal5 >>
+rect 0 34750 254 39593
+rect 14746 34750 15000 39593
+rect 6339 32546 10468 33417
+rect 0 13600 254 18590
+rect 14746 13600 15000 18590
+rect 0 12430 254 13280
+rect 14746 12430 15000 13280
+rect 0 11260 254 12110
+rect 14746 11260 15000 12110
+rect 0 9140 254 10940
+rect 14746 9140 15000 10940
+rect 0 7930 254 8820
+rect 14746 7930 15000 8820
+rect 0 6960 254 7610
+rect 14746 6960 15000 7610
+rect 0 5990 254 6640
+rect 14746 5990 15000 6640
+rect 0 4780 254 5670
+rect 14746 4780 15000 5670
+rect 0 3570 254 4460
+rect 14746 3570 15000 4460
+rect 0 2600 254 3250
+rect 14746 2600 15000 3250
+rect 0 1390 254 2280
+rect 14746 1390 15000 2280
+rect 0 20 254 1070
+rect 14746 20 15000 1070
+use sky130_ef_io__lvc_vccdy_overlay  sky130_ef_io__lvc_vccdy_overlay_0
+timestamp 1636574685
+transform 1 0 0 0 1 7
+box 4185 -2184 17187 39586
+use sky130_fd_io__top_power_lvc_wpad  sky130_fd_io__top_power_lvc_wpad_0 $PDKPATH/libs.ref/sky130_fd_io/mag
+timestamp 1636165381
+transform 1 0 0 0 1 -7
+box 0 0 15000 39600
+<< labels >>
+flabel metal4 s 14873 37925 14873 37925 3 FreeSans 520 180 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 127 37925 127 37925 3 FreeSans 520 0 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal3 s 10151 -7 14940 862 0 FreeSans 4000 0 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal3 s 100 -7 4900 862 0 FreeSans 2000 0 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal5 s 14746 9140 15000 10940 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal5 s 14807 2600 15000 3250 3 FreeSans 520 180 0 0 VDDA
+port 10 nsew power bidirectional
+flabel metal5 s 14746 7930 15000 8820 3 FreeSans 520 180 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal5 s 14746 11260 15000 12110 3 FreeSans 520 180 0 0 VSSIO_Q
+port 18 nsew ground bidirectional
+flabel metal5 s 14746 4780 15000 5670 3 FreeSans 520 180 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal5 s 14746 5990 15000 6640 3 FreeSans 520 180 0 0 VSWITCH
+port 11 nsew power bidirectional
+flabel metal5 s 14746 6961 15000 7610 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal5 s 14746 1390 15000 2280 3 FreeSans 520 180 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal5 s 14746 12430 15000 13280 3 FreeSans 520 180 0 0 VDDIO_Q
+port 12 nsew power bidirectional
+flabel metal5 s 14746 13600 15000 18590 3 FreeSans 520 180 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal5 s 14746 20 15000 1070 3 FreeSans 520 180 0 0 VCCHIB
+port 13 nsew power bidirectional
+flabel metal5 s 14746 3570 15000 4460 3 FreeSans 520 180 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal5 s 0 13600 254 18590 3 FreeSans 520 0 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal5 s 0 7930 254 8820 3 FreeSans 520 0 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal5 s 0 11260 254 12110 3 FreeSans 520 0 0 0 VSSIO_Q
+port 18 nsew ground bidirectional
+flabel metal5 s 0 5990 254 6640 3 FreeSans 520 0 0 0 VSWITCH
+port 11 nsew power bidirectional
+flabel metal5 s 0 4780 254 5670 3 FreeSans 520 0 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal5 s 0 2600 193 3250 3 FreeSans 520 0 0 0 VDDA
+port 10 nsew power bidirectional
+flabel metal5 s 0 3570 254 4460 3 FreeSans 520 0 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal5 s 0 1390 254 2280 3 FreeSans 520 0 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal5 s 0 12430 254 13280 3 FreeSans 520 0 0 0 VDDIO_Q
+port 12 nsew power bidirectional
+flabel metal5 s 0 9140 254 10940 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal5 s 0 6961 254 7610 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal5 s 0 20 254 1070 3 FreeSans 520 0 0 0 VCCHIB
+port 13 nsew power bidirectional
+flabel metal4 s 14746 7910 15000 8840 3 FreeSans 520 180 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal4 s 14807 2580 15000 3270 3 FreeSans 520 180 0 0 VDDA
+port 10 nsew power bidirectional
+flabel metal4 s 14746 11240 15000 12130 3 FreeSans 520 180 0 0 VSSIO_Q
+port 18 nsew ground bidirectional
+flabel metal4 s 14746 4760 15000 5690 3 FreeSans 520 180 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 14746 5970 15000 6660 3 FreeSans 520 180 0 0 VSWITCH
+port 11 nsew power bidirectional
+flabel metal4 s 14746 9922 15000 10158 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 14746 10874 15000 10940 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 14746 0 15000 1090 3 FreeSans 520 180 0 0 VCCHIB
+port 13 nsew power bidirectional
+flabel metal4 s 14746 3550 15000 4480 3 FreeSans 520 180 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal4 s 14746 9140 15000 9206 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 14746 6940 15000 7630 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 14746 12410 15000 13300 3 FreeSans 520 180 0 0 VDDIO_Q
+port 12 nsew power bidirectional
+flabel metal4 s 14746 1370 15000 2300 3 FreeSans 520 180 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal4 s 14746 9266 15000 9862 3 FreeSans 520 180 0 0 AMUXBUS_B
+port 1 nsew signal bidirectional
+flabel metal4 s 14746 34750 15000 39593 3 FreeSans 520 180 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 14746 10218 15000 10814 3 FreeSans 520 180 0 0 AMUXBUS_A
+port 0 nsew signal bidirectional
+flabel metal4 s 14746 13600 15000 18593 3 FreeSans 520 180 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal4 s 0 34750 254 39593 3 FreeSans 520 0 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 0 3550 254 4480 3 FreeSans 520 0 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal4 s 0 12410 254 13300 3 FreeSans 520 0 0 0 VDDIO_Q
+port 12 nsew power bidirectional
+flabel metal4 s 0 13600 254 18593 3 FreeSans 520 0 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal4 s 0 1370 254 2300 3 FreeSans 520 0 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal4 s 0 9140 254 9206 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 0 5970 254 6660 3 FreeSans 520 0 0 0 VSWITCH
+port 11 nsew power bidirectional
+flabel metal4 s 0 0 254 1090 3 FreeSans 520 0 0 0 VCCHIB
+port 13 nsew power bidirectional
+flabel metal4 s 0 9922 254 10158 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 0 11240 254 12130 3 FreeSans 520 0 0 0 VSSIO_Q
+port 18 nsew ground bidirectional
+flabel metal4 s 0 4760 254 5690 3 FreeSans 520 0 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 0 2580 193 3270 3 FreeSans 520 0 0 0 VDDA
+port 10 nsew power bidirectional
+flabel metal4 s 0 10218 254 10814 3 FreeSans 520 0 0 0 AMUXBUS_A
+port 0 nsew signal bidirectional
+flabel metal4 s 0 10874 254 10940 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 0 6940 254 7630 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 0 7910 254 8840 3 FreeSans 520 0 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal4 s 0 9266 254 9862 3 FreeSans 520 0 0 0 AMUXBUS_B
+port 1 nsew signal bidirectional
+flabel metal5 s 6339 32546 10468 33417 0 FreeSans 2000 0 0 0 VCCD_PAD
+port 2 nsew power bidirectional
+flabel metal2 10008 -1384 13676 -582 0 FreeSans 4800 0 0 0 VSSD1
+port 20 nsew ground bidirectional
+flabel metal3 318 -1432 4614 -598 0 FreeSans 4800 0 0 0 VCCD1
+port 19 nsew power bidirectional
+<< properties >>
+string LEFclass PAD POWER
+string FIXED_BBOX 0 0 15000 39593
+<< end >>

diff --git a/sky130/custom/sky130_fd_io/mag/sky130_ef_io__vssd_lvc_clamped3_pad.mag b/sky130/custom/sky130_fd_io/mag/sky130_ef_io__vssd_lvc_clamped3_pad.mag
new file mode 100644
index 0000000..b5e45b7
--- /dev/null
+++ b/sky130/custom/sky130_fd_io/mag/sky130_ef_io__vssd_lvc_clamped3_pad.mag

@@ -0,0 +1,245 @@
+magic
+tech sky130A
+magscale 1 2
+timestamp 1636574685
+<< checkpaint >>
+rect 1196 59263 3717 61784
+rect -1260 10928 16260 40853
+rect -1260 10766 18674 10928
+rect -4040 10286 18674 10766
+rect -4040 6546 19310 10286
+rect -4040 6192 18674 6546
+rect -1260 5974 18674 6192
+rect -1260 1695 16260 5974
+rect -1284 1027 16312 1695
+rect -1284 -2779 16322 1027
+rect -1284 -3149 16312 -2779
+rect -1233 -3156 16261 -3149
+rect 3849 -3158 16261 -3156
+rect 5751 -3162 16261 -3158
+rect 5751 -3184 9283 -3162
+<< metal1 >>
+rect 6867 95 7067 195
+rect 5242 -7 5540 83
+<< metal2 >>
+rect 101 0 4099 287
+rect 6888 -7 8888 58
+rect 10953 -7 14940 715
+<< via2 >>
+rect 681 5280 2029 14408
+rect 13709 5424 14473 14274
+<< metal3 >>
+rect 101 60 4900 862
+rect 100 -1896 4900 60
+rect 5200 68 7374 918
+rect 7676 68 9850 918
+rect 5200 -458 7376 68
+rect 7676 -458 9851 68
+rect 5200 -1898 9851 -458
+rect 10151 -1902 14940 862
+<< metal4 >>
+rect 0 34750 254 39593
+rect 14746 34750 15000 39593
+rect 0 13600 254 18593
+rect 14746 13600 15000 18593
+rect 0 12410 254 13300
+rect 14746 12410 15000 13300
+rect 0 11240 254 12130
+rect 14746 11240 15000 12130
+rect 0 10874 254 10940
+rect 14746 10874 15000 10940
+rect 0 10218 100 10814
+rect 14746 10218 14846 10814
+rect 0 9922 254 10158
+rect 14746 9922 15000 10158
+rect 0 9266 116 9862
+rect 14746 9266 14862 9862
+rect 0 9140 254 9206
+rect 14746 9140 15000 9206
+rect 0 7910 254 8840
+rect 14746 7910 15000 8840
+rect 0 6940 254 7630
+rect 14746 6940 15000 7630
+rect 0 5970 254 6660
+rect 14746 5970 15000 6660
+rect 0 4760 254 5690
+rect 14746 4760 15000 5690
+rect 0 3550 254 4480
+rect 14746 3550 15000 4480
+rect 0 2580 254 3270
+rect 14746 2580 15000 3270
+rect 0 1370 254 2300
+rect 14746 1370 15000 2300
+rect 0 0 254 1090
+rect 14746 0 15000 1090
+<< metal5 >>
+rect 0 34750 254 39593
+rect 14746 34750 15000 39593
+rect 6339 32546 10468 33417
+rect 0 13600 254 18590
+rect 14746 13600 15000 18590
+rect 0 12430 254 13280
+rect 14746 12430 15000 13280
+rect 0 11260 254 12110
+rect 14746 11260 15000 12110
+rect 0 9140 254 10940
+rect 14746 9140 15000 10940
+rect 0 7930 254 8820
+rect 14746 7930 15000 8820
+rect 0 6960 254 7610
+rect 14746 6960 15000 7610
+rect 0 5990 254 6640
+rect 14746 5990 15000 6640
+rect 0 4780 254 5670
+rect 14746 4780 15000 5670
+rect 0 3570 254 4460
+rect 14746 3570 15000 4460
+rect 0 2600 254 3250
+rect 14746 2600 15000 3250
+rect 0 1390 254 2280
+rect 14746 1390 15000 2280
+rect 0 20 254 1070
+rect 14746 20 15000 1070
+use sky130_ef_io__lvc_vccdy_overlay  sky130_ef_io__lvc_vccdy_overlay_0
+timestamp 1636574685
+transform 1 0 0 0 1 0
+box 4185 -2184 17187 39586
+use sky130_fd_io__top_ground_lvc_wpad  sky130_fd_io__top_ground_lvc_wpad_1 $PDKPATH/libs.ref/sky130_fd_io/mag
+timestamp 1636165381
+transform 1 0 0 0 1 -7
+box 0 0 15000 39600
+<< labels >>
+flabel metal4 s 14873 37925 14873 37925 3 FreeSans 520 180 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 127 37925 127 37925 3 FreeSans 520 0 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal3 s 10151 -7 14940 862 0 FreeSans 4000 0 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal3 s 100 -7 4900 862 0 FreeSans 2000 0 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal5 s 14746 9140 15000 10940 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal5 s 14807 2600 15000 3250 3 FreeSans 520 180 0 0 VDDA
+port 10 nsew power bidirectional
+flabel metal5 s 14746 7930 15000 8820 3 FreeSans 520 180 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal5 s 14746 11260 15000 12110 3 FreeSans 520 180 0 0 VSSIO_Q
+port 18 nsew ground bidirectional
+flabel metal5 s 14746 4780 15000 5670 3 FreeSans 520 180 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal5 s 14746 5990 15000 6640 3 FreeSans 520 180 0 0 VSWITCH
+port 11 nsew power bidirectional
+flabel metal5 s 14746 6961 15000 7610 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal5 s 14746 1390 15000 2280 3 FreeSans 520 180 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal5 s 14746 12430 15000 13280 3 FreeSans 520 180 0 0 VDDIO_Q
+port 12 nsew power bidirectional
+flabel metal5 s 14746 13600 15000 18590 3 FreeSans 520 180 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal5 s 14746 20 15000 1070 3 FreeSans 520 180 0 0 VCCHIB
+port 13 nsew power bidirectional
+flabel metal5 s 14746 3570 15000 4460 3 FreeSans 520 180 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal5 s 0 13600 254 18590 3 FreeSans 520 0 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal5 s 0 7930 254 8820 3 FreeSans 520 0 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal5 s 0 11260 254 12110 3 FreeSans 520 0 0 0 VSSIO_Q
+port 18 nsew ground bidirectional
+flabel metal5 s 0 5990 254 6640 3 FreeSans 520 0 0 0 VSWITCH
+port 11 nsew power bidirectional
+flabel metal5 s 0 4780 254 5670 3 FreeSans 520 0 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal5 s 0 2600 193 3250 3 FreeSans 520 0 0 0 VDDA
+port 10 nsew power bidirectional
+flabel metal5 s 0 3570 254 4460 3 FreeSans 520 0 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal5 s 0 1390 254 2280 3 FreeSans 520 0 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal5 s 0 12430 254 13280 3 FreeSans 520 0 0 0 VDDIO_Q
+port 12 nsew power bidirectional
+flabel metal5 s 0 9140 254 10940 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal5 s 0 6961 254 7610 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal5 s 0 20 254 1070 3 FreeSans 520 0 0 0 VCCHIB
+port 13 nsew power bidirectional
+flabel metal4 s 14746 7910 15000 8840 3 FreeSans 520 180 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal4 s 14807 2580 15000 3270 3 FreeSans 520 180 0 0 VDDA
+port 10 nsew power bidirectional
+flabel metal4 s 14746 11240 15000 12130 3 FreeSans 520 180 0 0 VSSIO_Q
+port 18 nsew ground bidirectional
+flabel metal4 s 14746 4760 15000 5690 3 FreeSans 520 180 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 14746 5970 15000 6660 3 FreeSans 520 180 0 0 VSWITCH
+port 11 nsew power bidirectional
+flabel metal4 s 14746 9922 15000 10158 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 14746 10874 15000 10940 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 14746 0 15000 1090 3 FreeSans 520 180 0 0 VCCHIB
+port 13 nsew power bidirectional
+flabel metal4 s 14746 3550 15000 4480 3 FreeSans 520 180 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal4 s 14746 9140 15000 9206 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 14746 6940 15000 7630 3 FreeSans 520 180 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 14746 12410 15000 13300 3 FreeSans 520 180 0 0 VDDIO_Q
+port 12 nsew power bidirectional
+flabel metal4 s 14746 1370 15000 2300 3 FreeSans 520 180 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal4 s 14746 9266 15000 9862 3 FreeSans 520 180 0 0 AMUXBUS_B
+port 1 nsew signal bidirectional
+flabel metal4 s 14746 34750 15000 39593 3 FreeSans 520 180 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 14746 10218 15000 10814 3 FreeSans 520 180 0 0 AMUXBUS_A
+port 0 nsew signal bidirectional
+flabel metal4 s 14746 13600 15000 18593 3 FreeSans 520 180 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal4 s 0 34750 254 39593 3 FreeSans 520 0 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 0 3550 254 4480 3 FreeSans 520 0 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal4 s 0 12410 254 13300 3 FreeSans 520 0 0 0 VDDIO_Q
+port 12 nsew power bidirectional
+flabel metal4 s 0 13600 254 18593 3 FreeSans 520 0 0 0 VDDIO
+port 14 nsew power bidirectional
+flabel metal4 s 0 1370 254 2300 3 FreeSans 520 0 0 0 VCCD
+port 15 nsew power bidirectional
+flabel metal4 s 0 9140 254 9206 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 0 5970 254 6660 3 FreeSans 520 0 0 0 VSWITCH
+port 11 nsew power bidirectional
+flabel metal4 s 0 0 254 1090 3 FreeSans 520 0 0 0 VCCHIB
+port 13 nsew power bidirectional
+flabel metal4 s 0 9922 254 10158 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 0 11240 254 12130 3 FreeSans 520 0 0 0 VSSIO_Q
+port 18 nsew ground bidirectional
+flabel metal4 s 0 4760 254 5690 3 FreeSans 520 0 0 0 VSSIO
+port 16 nsew ground bidirectional
+flabel metal4 s 0 2580 193 3270 3 FreeSans 520 0 0 0 VDDA
+port 10 nsew power bidirectional
+flabel metal4 s 0 10218 254 10814 3 FreeSans 520 0 0 0 AMUXBUS_A
+port 0 nsew signal bidirectional
+flabel metal4 s 0 10874 254 10940 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 0 6940 254 7630 3 FreeSans 520 0 0 0 VSSA
+port 9 nsew ground bidirectional
+flabel metal4 s 0 7910 254 8840 3 FreeSans 520 0 0 0 VSSD
+port 17 nsew ground bidirectional
+flabel metal4 s 0 9266 254 9862 3 FreeSans 520 0 0 0 AMUXBUS_B
+port 1 nsew signal bidirectional
+flabel metal5 s 6339 32546 10468 33417 0 FreeSans 2000 0 0 0 VSSD_PAD
+port 2 nsew ground bidirectional
+flabel metal3 5463 -1758 9733 -648 0 FreeSans 4800 0 0 0 VCCD1
+port 19 nsew power bidirectional
+flabel metal3 237 -1714 4719 -658 0 FreeSans 4800 0 0 0 VSSD1
+port 20 nsew ground bidirectional
+<< properties >>
+string LEFclass PAD POWER
+string FIXED_BBOX 0 0 15000 39593
+<< end >>

diff --git a/sky130/custom/sky130_fd_io/verilog/sky130_ef_io.v b/sky130/custom/sky130_fd_io/verilog/sky130_ef_io.v
index 7462169..7587ab0 100644
--- a/sky130/custom/sky130_fd_io/verilog/sky130_ef_io.v
+++ b/sky130/custom/sky130_fd_io/verilog/sky130_ef_io.v

@@ -1169,6 +1169,108 @@
 
 endmodule
 
+// sky130_ef_io__vccd_lvc_pad with pad and LV clamp connection to VCCD1,
+// pad negative connection to VSSD1, and back-to-back diodes connecting
+// VSSD1 to VSSIO
+
+module sky130_ef_io__vccd_lvc_clamped3_pad (AMUXBUS_A, AMUXBUS_B,
+	VSSA, VDDA, VSWITCH, VDDIO_Q, VCCHIB, VDDIO, VCCD, VCCD_PAD,
+	VSSIO, VSSD, VSSIO_Q, VCCD1, VSSD1
+);
+  inout AMUXBUS_A;
+  inout AMUXBUS_B;
+
+  inout VDDIO;	
+  inout VDDIO_Q;	
+  inout VDDA;
+  inout VCCD;
+  inout VCCD_PAD;
+  inout VSWITCH;
+  inout VCCHIB;
+  inout VSSA;
+  inout VSSD;
+  inout VSSIO_Q;
+  inout VSSIO;
+  inout VCCD1;
+  inout VSSD1;
+
+  // Instantiate the underlying power pad (connects P_PAD to VCCD1)
+  sky130_fd_io__top_power_lvc_wpad sky130_fd_io__top_power_lvc_base ( 
+	.VSSA(VSSA),
+	.VDDA(VDDA),
+	.VSWITCH(VSWITCH),
+	.VDDIO_Q(VDDIO_Q),
+	.VCCHIB(VCCHIB),
+	.VDDIO(VDDIO),
+	.VCCD(VCCD),
+	.VSSIO(VSSIO),
+	.VSSD(VSSD),
+	.VSSIO_Q(VSSIO_Q),
+	.P_CORE(VCCD1),
+	.P_PAD(VCCD_PAD),
+	.OGC_LVC(),
+	.BDY2_B2B(VSSIO),
+	.AMUXBUS_A(AMUXBUS_A),
+	.AMUXBUS_B(AMUXBUS_B),
+	.DRN_LVC1(VCCD1),
+	.DRN_LVC2(VCCD1),
+	.SRC_BDY_LVC1(VSSD1),
+	.SRC_BDY_LVC2(VSSD1)
+  );
+
+endmodule
+
+// sky130_ef_io__vssd_lvc_pad with pad and LV clamp negative connection
+// to VSSD1, clamp positive connection to VCCD1, and back-to-back diodes
+// connecting VSSD1 to VSSIO
+
+module sky130_ef_io__vssd_lvc_clamped3_pad (AMUXBUS_A, AMUXBUS_B,
+	VSSA, VDDA, VSWITCH, VDDIO_Q, VCCHIB, VDDIO, VCCD,
+	VSSIO, VSSD, VSSD_PAD, VSSIO_Q, VCCD1, VSSD1
+);
+  inout AMUXBUS_A;
+  inout AMUXBUS_B;
+
+  inout VDDIO;	
+  inout VDDIO_Q;	
+  inout VDDA;
+  inout VCCD;
+  inout VSWITCH;
+  inout VCCHIB;
+  inout VSSA;
+  inout VSSD;
+  inout VSSD_PAD;
+  inout VSSIO_Q;
+  inout VSSIO;
+  inout VCCD1;
+  inout VSSD1;
+
+  // Instantiate the underlying ground pad (connects G_PAD to VSSD1)
+  sky130_fd_io__top_ground_lvc_wpad sky130_fd_io__top_ground_lvc_base ( 
+	.VSSA(VSSA),
+	.VDDA(VDDA),
+	.VSWITCH(VSWITCH),
+	.VDDIO_Q(VDDIO_Q),
+	.VCCHIB(VCCHIB),
+	.VDDIO(VDDIO),
+	.VCCD(VCCD),
+	.VSSIO(VSSIO),
+	.VSSD(VSSD),
+	.VSSIO_Q(VSSIO_Q),
+	.G_CORE(VSSD1),
+	.G_PAD(VSSD_PAD),
+	.OGC_LVC(),
+	.BDY2_B2B(VSSIO),
+	.AMUXBUS_A(AMUXBUS_A),
+	.AMUXBUS_B(AMUXBUS_B),
+	.DRN_LVC1(VCCD1),
+	.DRN_LVC2(VCCD1),
+	.SRC_BDY_LVC1(VSSD1),
+	.SRC_BDY_LVC2(VSSD1)
+  );
+
+endmodule
+
 // 
 
 module sky130_ef_io__top_power_hvc (AMUXBUS_A, AMUXBUS_B, DRN_HVC,