From ce0202dda1b470c14f643ab4a0a3a276b4f28c16 Mon Sep 17 00:00:00 2001
From: Tim Edwards <tim@opencircuitdesign.com>
Date: Tue, 26 Nov 2024 22:38:06 -0500
Subject: [PATCH] Made various changes and additions to the device generator
 scripts for magic for sky130: 1) Added internal spacing between the 3.3V nfet
 device and guard    ring so that multiple cells can be abutted without
 causing an    HVNTM spacing error. 2) Corrected missing vias over contacts
 for snake resistors 3) Added port labels to most of the device types (which
 should make    LVS easier) 4) Added an option to the lower MiM cap to
 increase the internal    spacings in a cap array so that it becomes
 compatible with the    upper MiM cap spacing, so that MiM caps can be easily
 stacked.

---
 sky130/magic/sky130.tcl | 393 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 346 insertions(+), 47 deletions(-)

diff --git a/sky130/magic/sky130.tcl b/sky130/magic/sky130.tcl
index 736e82a9..69b6b221 100644
--- a/sky130/magic/sky130.tcl
+++ b/sky130/magic/sky130.tcl
@@ -1052,6 +1052,10 @@ proc sky130::diode_dialog {device parameters} {
 
     magic::add_dependency sky130::diode_recalc $device sky130 l w area peri
 
+    if {[dict exists $parameters addports]} {
+	magic::add_checkbox doports "Add ports" $parameters
+    }
+
     # magic::add_checkbox dummy "Add dummy" $parameters
 }
 
@@ -1172,7 +1176,7 @@ proc sky130::sky130_fd_pr__diode_pw2nd_05v5_defaults {} {
 	elc 1 erc 1 etc 1 ebc 1 doverlap 0 \
 	compatible {sky130_fd_pr__diode_pw2nd_05v5 sky130_fd_pr__diode_pw2nd_05v5_lvt \
 	sky130_fd_pr__diode_pw2nd_05v5_nvt sky130_fd_pr__diode_pw2nd_11v0} \
-	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0}
+	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__diode_pw2nd_05v5_lvt_defaults {} {
@@ -1181,7 +1185,7 @@ proc sky130::sky130_fd_pr__diode_pw2nd_05v5_lvt_defaults {} {
 	elc 1 erc 1 etc 1 ebc 1 doverlap 0 \
 	compatible {sky130_fd_pr__diode_pw2nd_05v5 sky130_fd_pr__diode_pw2nd_05v5_lvt \
 	sky130_fd_pr__diode_pw2nd_05v5_nvt sky130_fd_pr__diode_pw2nd_11v0} \
-	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0}
+	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__diode_pw2nd_05v5_nvt_defaults {} {
@@ -1190,7 +1194,7 @@ proc sky130::sky130_fd_pr__diode_pw2nd_05v5_nvt_defaults {} {
 	elc 1 erc 1 etc 1 ebc 1 doverlap 0 \
 	compatible {sky130_fd_pr__diode_pw2nd_05v5 sky130_fd_pr__diode_pw2nd_05v5_lvt \
 	sky130_fd_pr__diode_pw2nd_05v5_nvt sky130_fd_pr__diode_pw2nd_11v0} \
-	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0}
+	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__diode_pw2nd_11v0_defaults {} {
@@ -1199,7 +1203,7 @@ proc sky130::sky130_fd_pr__diode_pw2nd_11v0_defaults {} {
 	elc 1 erc 1 etc 1 ebc 1 doverlap 0 \
 	compatible {sky130_fd_pr__diode_pw2nd_05v5 sky130_fd_pr__diode_pw2nd_05v5_lvt \
 	sky130_fd_pr__diode_pw2nd_05v5_nvt sky130_fd_pr__diode_pw2nd_11v0} \
-	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0}
+	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__photodiode_defaults {} {
@@ -1213,7 +1217,7 @@ proc sky130::sky130_fd_pr__diode_pd2nw_05v5_defaults {} {
 	glc 1 grc 1 gtc 1 gbc 1 doverlap 0 \
 	compatible {sky130_fd_pr__diode_pd2nw_05v5 sky130_fd_pr__diode_pd2nw_05v5_lvt \
 	sky130_fd_pr__diode_pd2nw_05v5_hvt sky130_fd_pr__diode_pd2nw_11v0} \
-	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0}
+	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__diode_pd2nw_05v5_lvt_defaults {} {
@@ -1223,7 +1227,7 @@ proc sky130::sky130_fd_pr__diode_pd2nw_05v5_lvt_defaults {} {
 	glc 1 grc 1 gtc 1 gbc 1 doverlap 0 \
 	compatible {sky130_fd_pr__diode_pd2nw_05v5 sky130_fd_pr__diode_pd2nw_05v5_lvt \
 	sky130_fd_pr__diode_pd2nw_05v5_hvt sky130_fd_pr__diode_pd2nw_11v0} \
-	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0}
+	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__diode_pd2nw_05v5_hvt_defaults {} {
@@ -1233,7 +1237,7 @@ proc sky130::sky130_fd_pr__diode_pd2nw_05v5_hvt_defaults {} {
 	glc 1 grc 1 gtc 1 gbc 1 doverlap 0 \
 	compatible {sky130_fd_pr__diode_pd2nw_05v5 sky130_fd_pr__diode_pd2nw_05v5_lvt \
 	sky130_fd_pr__diode_pd2nw_05v5_hvt sky130_fd_pr__diode_pd2nw_11v0} \
-	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0}
+	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 
@@ -1244,7 +1248,7 @@ proc sky130::sky130_fd_pr__diode_pd2nw_11v0_defaults {} {
 	glc 1 grc 1 gtc 1 gbc 1 doverlap 0 \
 	compatible {sky130_fd_pr__diode_pd2nw_05v5 sky130_fd_pr__diode_pd2nw_05v5_lvt \
 	sky130_fd_pr__diode_pd2nw_05v5_hvt sky130_fd_pr__diode_pd2nw_11v0} \
-	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0}
+	full_metal 1 vias 1 viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 #----------------------------------------------------------------
@@ -1370,9 +1374,13 @@ proc sky130::diode_device {parameters} {
     set eps  0.0005
 
     # Set local default values if they are not in parameters
+    set doports 0	;# no port labels by default
     set dev_surround 0
     set dev_sub_type ""
 
+    set term_d ""	;# diffusion
+    set term_s ""	;# substrate/well
+
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
         set $key [dict get $parameters $key]
@@ -1406,6 +1414,12 @@ proc sky130::diode_device {parameters} {
     dict set guardparams grc $erc
     dict set guardparams gtc $etc
     dict set guardparams gbc $ebc
+
+    if {$term_s != ""} {
+	dict set guardparams bulk $term_s
+    } else {
+	dict unset guardparams bulk
+    }
     set cext [sky130::guard_ring $gx $gy $guardparams]
 
     pushbox
@@ -1425,6 +1439,13 @@ proc sky130::diode_device {parameters} {
     }
     popbox
 
+    # Diffusion port label
+    if {$term_d != ""} {
+	label $term_d c $dev_type
+	select area label
+	port make
+    }
+
     if {${w} < ${l}} {
 	set orient vert
     } else {
@@ -1468,6 +1489,7 @@ proc sky130::diode_draw {parameters} {
     set doverlap 0	;# overlap diodes at contacts
     set guard 0		;# draw a guard ring
     set prohibit_overlap false  ;# don't prohibit overlaps
+    set doports 0
 
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
@@ -1527,6 +1549,7 @@ proc sky130::diode_draw {parameters} {
 	set gy [+ $corey [* 2.0 [+ $diff_spacing $diff_surround]] $contact_size]
 
 	# Draw the guard ring first, because diode may occupy well/substrate plane
+	if {$doports} {dict set parameters bulk B}
 	sky130::guard_ring $gx $gy $parameters
     }
 
@@ -1546,6 +1569,22 @@ proc sky130::diode_draw {parameters} {
     for {set xp 0} {$xp < $nx} {incr xp} {
 	pushbox
 	for {set yp 0} {$yp < $ny} {incr yp} {
+	    if {$doports} {
+		if {($ny == 1) && ($nx == 1)} {
+		    dict set parameters term_d D1
+		} elseif {$ny == 1} {
+		    dict set parameters term_d D1_$xp
+		} elseif {$nx == 1} {
+		    dict set parameters term_d D1_$yp
+		} else {
+		    dict set parameters term_d D1_${xp}_$yp
+		}
+		if {($xp == 0) && ($yp == 0)} {
+		    dict set parameters term_s D2
+		} else {
+		    dict set parameters term_s ""
+		}
+	    }
 	    sky130::diode_device $parameters
             box move n ${dy}um
         }
@@ -1564,6 +1603,8 @@ proc sky130::diode_draw {parameters} {
 
 proc sky130::photodiode_device {parameters} {
 
+    set doports 0	;# no port labels by default
+
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
         set $key [dict get $parameters $key]
@@ -1953,13 +1994,13 @@ proc sky130::sky130_fd_pr__cap_mim_m3_1_defaults {} {
     return {w 2.00 l 2.00 val 8.0 carea 2.00 cperi 0.19 class capacitor \
 		nx 1 ny 1 dummy 0 square 0 lmin 2.00 wmin 2.00 \
 		lmax 30.0 wmax 30.0 dc 0 bconnect 1 tconnect 1 \
-		ccov 100}
+		ccov 100 stack 1 doports 1}
 }
 proc sky130::sky130_fd_pr__cap_mim_m3_2_defaults {} {
     return {w 2.00 l 2.00 val 8.0 carea 2.00 cperi 0.19 class capacitor \
 		nx 1 ny 1 dummy 0 square 0 lmin 2.00 wmin 2.00 \
 		lmax 30.0 wmax 30.0 dc 0 bconnect 1 tconnect 1 \
-		ccov 100}
+		ccov 100 doports 1}
 }
 #endif (MIM)
 
@@ -2074,9 +2115,16 @@ proc sky130::cap_dialog {device parameters} {
     if {[dict exists $parameters guard]} {
 	magic::add_checkbox guard "Add guard ring" $parameters
     }
+    if {[dict exists $parameters stack]} {
+	magic::add_checkbox stack "Stacked cap compatibility" $parameters
+    }
 
     magic::add_dependency sky130::cap_recalc $device sky130 l w val
 
+    if {[dict exists $parameters addports]} {
+	magic::add_checkbox doports "Add ports" $parameters
+    }
+
     # magic::add_checkbox dummy "Add dummy" $parameters
 }
 
@@ -2113,6 +2161,7 @@ proc sky130::cap_device {parameters} {
     set eps  0.0005
 
     # Set local default values if they are not in parameters
+    set doports 0	;# no port labels by default
     set cap_surround 0
     set bot_surround 0
     set top_surround 0
@@ -2124,6 +2173,9 @@ proc sky130::cap_device {parameters} {
     set contact_size 0	    ;# cap contact minimum size
     set ccov 100	    ;# amount of contact coverage
 
+    set term_t ""
+    set term_b ""
+
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
         set $key [dict get $parameters $key]
@@ -2239,9 +2291,21 @@ proc sky130::cap_device {parameters} {
     set cext [sky130::unionbox $cext [sky130::draw_contact 0 ${cl} \
 		${end_surround} ${metal_surround} ${contact_size} \
 		${bot_type} ${top_contact_type} ${top_type} full]]
+    # Bottom plate port label
+    if {$term_b != ""} {
+	label $term_b c $bot_type
+	select area label
+	port make
+    }
     popbox
     popbox
 
+    # Top plate port label
+    if {$term_t != ""} {
+	label $term_t c $top_type
+	select area label
+	port make
+    }
     return $cext
 
     # cl shrinks top and bottom to accomodate larger bottom metal
@@ -2255,6 +2319,8 @@ proc sky130::cap_device {parameters} {
 
 proc sky130::sandwich_cap_device {parameters} {
 
+    set doports 0	;# no port labels by default
+
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
         set $key [dict get $parameters $key]
@@ -2475,12 +2541,14 @@ proc sky130::cap_draw {parameters} {
     set wide_cap_spacing 0  ;# additional spacing for wide metal rule
     set wide_cap_width 0
     set end_spacing 0
+    set extra_spacing 0
     set end_surround 0
     set bot_surround 0
     set top_metal_width 0
     set bconnect 0	;# connect bottom plates in array
     set tconnect 0	;# connect top plates in array
     set top_type ""
+    set doports 0
 
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
@@ -2526,7 +2594,7 @@ proc sky130::cap_draw {parameters} {
         set dy [- $fh [+ $end_surround $end_surround $contact_size]]
     }
     # Contact is placed on right so spacing is determined by end_spacing.
-    set dx [+ $fw $end_spacing $dwide]
+    set dx [+ $fw $end_spacing $extra_spacing $dwide]
 
     # Determine core width and height
     set corex [+ [* [- $nx 1] $dx] $fw]
@@ -2540,6 +2608,7 @@ proc sky130::cap_draw {parameters} {
 	set gy [+ $corey [* 2.0 [+ $end_spacing $diff_surround]] $contact_size]
 
 	# Draw the guard ring first.
+	if {$doports} {dict set parameters bulk B}
 	sky130::guard_ring $gx $gy $parameters
     }
 
@@ -2557,6 +2626,41 @@ proc sky130::cap_draw {parameters} {
     for {set xp 0} {$xp < $nx} {incr xp} {
 	pushbox
 	for {set yp 0} {$yp < $ny} {incr yp} {
+	    if {$doports} {
+		if {($ny == 1) && ($nx == 1)} {
+		    dict set parameters term_t C1
+		    dict set parameters term_b C2
+		} elseif {$ny == 1} {
+		    dict set parameters term_t C1_$xp
+		    dict set parameters term_b C2_$xp
+		} elseif {$nx == 1} {
+		    if {$tconnect} {
+			dict set parameters term_t C1
+		    } else {
+			dict set parameters term_t C1_$yp
+		    }
+		    if {$bconnect} {
+			dict set parameters term_b C2
+		    } else {
+			dict set parameters term_b C2_$yp
+		    }
+		} else {
+		    if {$tconnect} {
+		    	dict set parameters term_t C1_$xp
+		    } else {
+		    	dict set parameters term_t C1_${xp}_$yp
+		    }
+		    if {$bconnect} {
+		    	dict set parameters term_b C2_$xp
+		    } else {
+		    	dict set parameters term_b C2_${xp}_$yp
+		    }
+		}
+		if {$yp > 0} {
+		    if {$tconnect} {dict set parameters term_t ""}
+		    if {$bconnect} {dict set parameters term_b ""}
+		}
+	    }
 	    if {$sandwich == 1} {
 		sky130::sandwich_cap_device $parameters
 	    } else {
@@ -2593,6 +2697,23 @@ proc sky130::cap_draw {parameters} {
 
 #ifdef MIM
 proc sky130::sky130_fd_pr__cap_mim_m3_1_draw {parameters} {
+    set stack 0
+
+    # Set a local variable for each parameter
+    foreach key [dict keys $parameters] {
+        set $key [dict get $parameters $key]
+    }
+    if {$stack} {
+	# For cap stacking, dimensions are increased to match the mim2 device
+	set capspace 1.6
+	set capextra 1.83
+	set endspace 1.5
+    } else {
+	set capspace 1.2
+	set capextra 0.0
+	set endspace 1.2
+    }
+
     set newdict [dict create \
 	    top_type 		m4 \
 	    top_contact_type	via3 \
@@ -2600,11 +2721,12 @@ proc sky130::sky130_fd_pr__cap_mim_m3_1_draw {parameters} {
 	    cap_contact_type	mimcc \
 	    bot_type 		m3 \
 	    bot_surround	0.2 \
-	    cap_spacing		1.2 \
+	    cap_spacing		${capspace} \
+	    extra_spacing	${capextra} \
 	    cap_surround	0.2 \
 	    top_surround	0.005 \
 	    end_surround	0.1 \
-	    end_spacing		1.2 \
+	    end_spacing		${endspace} \
 	    contact_size	0.32 \
 	    metal_surround	0.08 \
     ]
@@ -2764,7 +2886,7 @@ proc sky130::sky130_fd_pr__res_iso_pw_defaults {} {
     return {w 2.650 l 26.50 m 1 nx 1 wmin 2.650 lmin 26.50 class resistor \
 	 	rho 3050 val 30502 dummy 0 dw 0.25 term 1.0 \
 		guard 1 endcov 100 full_metal 1 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 #----------------------------------------------------------------
@@ -2778,7 +2900,7 @@ proc sky130::sky130_fd_pr__res_generic_po_defaults {} {
 		sterm 0.0 caplen 0.4 snake 0 guard 1 \
 		glc 1 grc 1 gtc 1 gbc 1 roverlap 0 endcov 100 \
 		full_metal 1 hv_guard 0 n_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 # "term" is rho * 0.06, the distance between xpc edge and CONT.
@@ -2790,7 +2912,7 @@ proc sky130::sky130_fd_pr__res_high_po_0p35_defaults {} {
 		sky130_fd_pr__res_high_po_0p69 sky130_fd_pr__res_high_po_1p41 \
 		sky130_fd_pr__res_high_po_2p85 sky130_fd_pr__res_high_po_5p73} \
 		snake 0 full_metal 1 wmax 0.350 vias 1 n_guard 0 hv_guard 0 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 proc sky130::sky130_fd_pr__res_high_po_0p69_defaults {} {
     return {w 0.690 l 1.00 m 1 nx 1 wmin 0.690 lmin 0.50 class resistor \
@@ -2800,7 +2922,7 @@ proc sky130::sky130_fd_pr__res_high_po_0p69_defaults {} {
 		sky130_fd_pr__res_high_po_0p69 sky130_fd_pr__res_high_po_1p41 \
 		sky130_fd_pr__res_high_po_2p85 sky130_fd_pr__res_high_po_5p73} \
 		snake 0 full_metal 1 wmax 0.690 n_guard 0 hv_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 proc sky130::sky130_fd_pr__res_high_po_1p41_defaults {} {
     return {w 1.410 l 2.00 m 1 nx 1 wmin 1.410 lmin 0.50 class resistor \
@@ -2810,7 +2932,7 @@ proc sky130::sky130_fd_pr__res_high_po_1p41_defaults {} {
 		sky130_fd_pr__res_high_po_0p69 sky130_fd_pr__res_high_po_1p41 \
 		sky130_fd_pr__res_high_po_2p85 sky130_fd_pr__res_high_po_5p73} \
 		snake 0 full_metal 1 wmax 1.410 n_guard 0 hv_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 proc sky130::sky130_fd_pr__res_high_po_2p85_defaults {} {
     return {w 2.850 l 3.00 m 1 nx 1 wmin 2.850 lmin 0.50 class resistor \
@@ -2820,7 +2942,7 @@ proc sky130::sky130_fd_pr__res_high_po_2p85_defaults {} {
 		sky130_fd_pr__res_high_po_0p69 sky130_fd_pr__res_high_po_1p41 \
 		sky130_fd_pr__res_high_po_2p85 sky130_fd_pr__res_high_po_5p73} \
 		snake 0 full_metal 1 wmax 2.850 n_guard 0 hv_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 proc sky130::sky130_fd_pr__res_high_po_5p73_defaults {} {
     return {w 5.730 l 6.00 m 1 nx 1 wmin 5.730 lmin 0.50 class resistor \
@@ -2830,7 +2952,7 @@ proc sky130::sky130_fd_pr__res_high_po_5p73_defaults {} {
 		sky130_fd_pr__res_high_po_0p69 sky130_fd_pr__res_high_po_1p41 \
 		sky130_fd_pr__res_high_po_2p85 sky130_fd_pr__res_high_po_5p73} \
 		snake 0 full_metal 1 wmax 5.730 n_guard 0 hv_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 # "term" is rho * 0.06, the distance between xpc edge and CONT.
@@ -2843,7 +2965,7 @@ proc sky130::sky130_fd_pr__res_xhigh_po_0p35_defaults {} {
 		sky130_fd_pr__res_xhigh_po_0p69 sky130_fd_pr__res_xhigh_po_1p41 \
 		sky130_fd_pr__res_xhigh_po_2p85 sky130_fd_pr__res_xhigh_po_5p73} \
 		snake 0 full_metal 1 n_guard 0 hv_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 proc sky130::sky130_fd_pr__res_xhigh_po_0p69_defaults {} {
     return {w 0.690 l 1.00 m 1 nx 1 wmin 0.690 lmin 0.50 class resistor \
@@ -2854,7 +2976,7 @@ proc sky130::sky130_fd_pr__res_xhigh_po_0p69_defaults {} {
 		sky130_fd_pr__res_xhigh_po_0p69 sky130_fd_pr__res_xhigh_po_1p41 \
 		sky130_fd_pr__res_xhigh_po_2p85 sky130_fd_pr__res_xhigh_po_5p73} \
 		snake 0 full_metal 1 n_guard 0 hv_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 proc sky130::sky130_fd_pr__res_xhigh_po_1p41_defaults {} {
     return {w 1.410 l 2.00 m 1 nx 1 wmin 1.410 lmin 0.50 class resistor \
@@ -2865,7 +2987,7 @@ proc sky130::sky130_fd_pr__res_xhigh_po_1p41_defaults {} {
 		sky130_fd_pr__res_xhigh_po_0p69 sky130_fd_pr__res_xhigh_po_1p41 \
 		sky130_fd_pr__res_xhigh_po_2p85 sky130_fd_pr__res_xhigh_po_5p73} \
 		snake 0 full_metal 1 n_guard 0 hv_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 proc sky130::sky130_fd_pr__res_xhigh_po_2p85_defaults {} {
     return {w 2.850 l 3.00 m 1 nx 1 wmin 2.850 lmin 0.50 class resistor \
@@ -2876,7 +2998,7 @@ proc sky130::sky130_fd_pr__res_xhigh_po_2p85_defaults {} {
 		sky130_fd_pr__res_xhigh_po_0p69 sky130_fd_pr__res_xhigh_po_1p41 \
 		sky130_fd_pr__res_xhigh_po_2p85 sky130_fd_pr__res_xhigh_po_5p73} \
 		snake 0 full_metal 1 n_guard 0 hv_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 proc sky130::sky130_fd_pr__res_xhigh_po_5p73_defaults {} {
     return {w 5.730 l 6.00 m 1 nx 1 wmin 5.730 lmin 0.50 class resistor \
@@ -2887,7 +3009,7 @@ proc sky130::sky130_fd_pr__res_xhigh_po_5p73_defaults {} {
 		sky130_fd_pr__res_xhigh_po_0p69 sky130_fd_pr__res_xhigh_po_1p41 \
 		sky130_fd_pr__res_xhigh_po_2p85 sky130_fd_pr__res_xhigh_po_5p73} \
 		snake 0 full_metal 1 n_guard 0 hv_guard 0 vias 1 \
-		viagb 0 viagt 0 viagl 0 viagr 0}
+		viagb 0 viagt 0 viagl 0 viagr 0 doports 1}
 }
 
 #----------------------------------------------------------------
@@ -2900,7 +3022,7 @@ proc sky130::sky130_fd_pr__res_generic_nd_defaults {} {
 		rho 120 val 600.0 dummy 0 dw 0.05 term 0.0 \
 		sterm 0.0 caplen 0.4 snake 0 guard 1 \
 		glc 1 grc 1 gtc 1 gbc 1 roverlap 0 endcov 100 \
-		full_metal 1 vias 1 \
+		full_metal 1 vias 1 doports 1 \
 		viagb 0 viagt 0 viagl 0 viagr 0}
 }
 
@@ -2909,7 +3031,7 @@ proc sky130::sky130_fd_pr__res_generic_nd__hv_defaults {} {
 		rho 120 val 600.0 dummy 0 dw 0.02 term 0.0 \
 		sterm 0.0 caplen 0.4 snake 0 guard 1 \
 		glc 1 grc 1 gtc 1 gbc 1 roverlap 0 endcov 100 \
-		full_metal 1 vias 1 \
+		full_metal 1 vias 1 doports 1 \
 		viagb 0 viagt 0 viagl 0 viagr 0}
 }
 
@@ -2923,7 +3045,7 @@ proc sky130::sky130_fd_pr__res_generic_pd_defaults {} {
 		rho 197 val 985.0 dummy 0 dw 0.02 term 0.0 \
 		sterm 0.0 caplen 0.60 snake 0 guard 1 \
 		glc 1 grc 1 gtc 1 gbc 1 roverlap 0 endcov 100 \
-		full_metal 1 vias 1 \
+		full_metal 1 vias 1 doports 1 \
 		viagb 0 viagt 0 viagl 0 viagr 0}
 }
 
@@ -2932,7 +3054,7 @@ proc sky130::sky130_fd_pr__res_generic_pd__hv_defaults {} {
 		rho 197 val 985.0 dummy 0 dw 0.02 term 0.0 \
 		sterm 0.0 caplen 0.60 snake 0 guard 1 \
 		glc 1 grc 1 gtc 1 gbc 1 roverlap 0 endcov 100 \
-		full_metal 1 vias 1 \
+		full_metal 1 vias 1 doports 1 \
 		viagb 0 viagt 0 viagl 0 viagr 0}
 }
 
@@ -2944,7 +3066,7 @@ proc sky130::sky130_fd_pr__res_generic_pd__hv_defaults {} {
 proc sky130::sky130_fd_pr__res_generic_l1_defaults {} {
     return {w 0.170 l 0.170 m 1 nx 1 wmin 0.17 lmin 0.17 class resistor \
 		rho 12.8 val 12.8 dummy 0 dw 0.0 term 0.0 snake 0 \
-		roverlap 0}
+		roverlap 0 doports 1}
 }
 
 #----------------------------------------------------------------
@@ -2955,7 +3077,7 @@ proc sky130::sky130_fd_pr__res_generic_l1_defaults {} {
 proc sky130::sky130_fd_pr__res_generic_m1_defaults {} {
     return {w 0.140 l 0.140 m 1 nx 1 wmin 0.14 lmin 0.14 class resistor \
 		rho 0.125 val 0.125 dummy 0 dw 0.0 term 0.0 \
-		roverlap 0}
+		roverlap 0 doports 1}
 }
 
 #----------------------------------------------------------------
@@ -2966,7 +3088,7 @@ proc sky130::sky130_fd_pr__res_generic_m1_defaults {} {
 proc sky130::sky130_fd_pr__res_generic_m2_defaults {} {
     return {w 0.140 l 0.140 m 1 nx 1 wmin 0.14 lmin 0.14 class resistor \
 		rho 0.125 val 0.125 dummy 0 dw 0.0 term 0.0 \
-		roverlap 0}
+		roverlap 0 doports 1}
 }
 
 #----------------------------------------------------------------
@@ -2977,7 +3099,7 @@ proc sky130::sky130_fd_pr__res_generic_m2_defaults {} {
 proc sky130::sky130_fd_pr__res_generic_m3_defaults {} {
     return {w 0.300 l 0.300 m 1 nx 1 wmin 0.30 lmin 0.30 class resistor \
 		rho 0.047 val 0.047 dummy 0 dw 0.0 term 0.0 \
-		roverlap 0}
+		roverlap 0 doports 1}
 }
 
 #----------------------------------------------------------------
@@ -2989,12 +3111,12 @@ proc sky130::sky130_fd_pr__res_generic_m3_defaults {} {
 proc sky130::sky130_fd_pr__res_generic_m4_defaults {} {
     return {w 0.300 l 0.300 m 1 nx 1 wmin 0.30 lmin 0.30 class resistor \
 		rho 0.047 val 0.047 dummy 0 dw 0.0 term 0.0 \
-		roverlap 0}
+		roverlap 0 doports 1}
 }
 proc sky130::sky130_fd_pr__res_generic_m5_defaults {} {
     return {w 1.600 l 1.600 m 1 nx 1 wmin 1.60 lmin 1.60 class resistor \
 		rho 0.029 val 0.029 dummy 0 dw 0.0 term 0.0 \
-		roverlap 0}
+		roverlap 0 doports 1}
 }
 #endif (METAL5)
 
@@ -3185,6 +3307,10 @@ proc sky130::res_dialog {device parameters} {
     } else {
        magic::add_dependency sky130::res_recalc $device sky130 l w val nx
     }
+
+    if {[dict exists $parameters addports]} {
+	magic::add_checkbox doports "Add ports" $parameters
+    }
 }
 
 #----------------------------------------------------------------
@@ -3279,6 +3405,7 @@ proc sky130::res_device {parameters} {
     set eps  0.0005
 
     # Set local default values if they are not in parameters
+    set doports 0		;# no port labels by default
     set endcov 0	 	;# percent coverage of end contacts
     set roverlap 0		;# overlap resistors at end contacts
     set well_res_overlap 0 	;# not a well resistor
@@ -3288,6 +3415,9 @@ proc sky130::res_device {parameters} {
     set l_delta 0		;# delta between measured and drawn length
     set res_idtype none
 
+    set term_t ""
+    set term_b ""
+
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
         set $key [dict get $parameters $key]
@@ -3384,6 +3514,11 @@ proc sky130::res_device {parameters} {
     set cext [sky130::unionbox $cext [sky130::getbox]]
     popbox
 
+    if {$term_t != ""} {
+	label $term_t c $end_type
+	select area label
+	port make
+    }
     if {${end_contact_type} != ""} {
 	# Draw via over contact first
 	if {$vias != 0} {
@@ -3420,6 +3555,11 @@ proc sky130::res_device {parameters} {
     set cext [sky130::unionbox $cext [sky130::getbox]]
     popbox
 
+    if {$term_b != ""} {
+	label $term_b c $end_type
+	select area label
+	port make
+    }
     if {${end_contact_type} != ""} {
 	# Draw via over contact first
 	if {$vias != 0} {
@@ -3456,11 +3596,16 @@ proc sky130::res_snake_device {nf parameters} {
     set eps  0.0005
 
     # Set local default values if they are not in parameters
+    set doports 0		;# no port labels by default
     set endcov 100	 	;# percent coverage of end contacts
+    set vias 0			;# add vias over terminal contacts
     set well_res_overlap 0 	;# not a well resistor
     set end_contact_type ""	;# no contacts for metal resistors
     set mask_clearance 0	;# additional length to clear mask
 
+    set term_t ""
+    set term_b ""
+
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
         set $key [dict get $parameters $key]
@@ -3514,7 +3659,26 @@ proc sky130::res_snake_device {nf parameters} {
     set cext [sky130::getbox]
     popbox
 
+    if {$term_t != ""} {
+	label $term_t c $end_type
+	select area label
+	port make
+    }
     if {${end_contact_type} != ""} {
+	# Draw via over contact first
+	if {$vias != 0} {
+            pushbox
+            set ch $res_to_endcont
+    	    if {$ch < $via_size} {set ch $via_size}
+    	    set cw $epl
+    	    if {$cw < $via_size} {set cw $via_size}
+	    box grow n [- $ch [/ $via_size 2]]um
+	    box grow s [/ $via_size 2]um
+	    box grow w [/ $cw 2]um
+	    box grow e [/ $cw 2]um
+            sky130::mcon_draw
+            popbox
+    	}
 	set cext [sky130::draw_contact ${cpl} 0 \
 		${end_surround} ${metal_surround} ${end_contact_size} \
 		${end_type} ${end_contact_type} li horz]
@@ -3607,7 +3771,31 @@ proc sky130::res_snake_device {nf parameters} {
     set cext [sky130::unionbox $cext [sky130::getbox]]
     popbox
 
+    if {$term_b != ""} {
+	label $term_b c $end_type
+	select area label
+	port make
+    }
     if {${end_contact_type} != ""} {
+	# Draw via over contact first
+	if {$vias != 0} {
+            pushbox
+            set ch $res_to_endcont
+    	    if {$ch < $via_size} {set ch $via_size}
+    	    set cw $epl
+    	    if {$cw < $via_size} {set cw $via_size}
+	    if {$dir == "n"} {
+		box grow n [/ $via_size 2]um
+		box grow s [- $ch [/ $via_size 2]]um
+	    } else {
+		box grow n [- $ch [/ $via_size 2]]um
+		box grow s [/ $via_size 2]um
+	    }
+	    box grow w [/ $cw 2]um
+	    box grow e [/ $cw 2]um
+            sky130::mcon_draw
+            popbox
+    	}
 	set cext [sky130::unionbox $cext [sky130::draw_contact ${cpl} 0 \
 		${end_surround} ${metal_surround} ${end_contact_size} \
 		${end_type} ${end_contact_type} li horz]]
@@ -3656,6 +3844,7 @@ proc sky130::res_draw {parameters} {
     set well_res_overlap 0	;# additional well extension behind contact
     set res_diff_spacing 0	;# spacing from resistor to diffusion
     set res_idtype  none
+    set doports 0
 
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
@@ -3734,6 +3923,7 @@ proc sky130::res_draw {parameters} {
 	set gy [+ $corey [* 2.0 [+ $end_spacing $guard_diff_surround]] $contact_size]
 
 	# Draw the guard ring first, because well resistors are on the substrate plane
+	if {$doports} {dict set parameters bulk B}
 	sky130::guard_ring $gx $gy $parameters
     }
 
@@ -3744,6 +3934,21 @@ proc sky130::res_draw {parameters} {
     for {set xp 0} {$xp < $nx} {incr xp} {
 	pushbox
 	for {set yp 0} {$yp < $m} {incr yp} {
+	    if {$doports} {
+		if {($m == 1) && ($nx == 1)} {
+		     dict set parameters term_t R1
+		     dict set parameters term_b R2
+		} elseif {$m == 1} {
+		     dict set parameters term_t R1_$xp
+		     dict set parameters term_b R2_$xp
+		} elseif {$nx == 1} {
+		     dict set parameters term_t R1_$yp
+		     dict set parameters term_b R2_$yp
+		} else {
+		     dict set parameters term_t R1_${xp}_$yp
+		     dict set parameters term_b R2_${xp}_$yp
+		}
+	    }
 	    if {$snake == 1} {
 		sky130::res_snake_device $nf $parameters
 	    } else {
@@ -5223,7 +5428,7 @@ proc sky130::sky130_fd_pr__pfet_01v8_defaults {} {
 		sky130_fd_pr__pfet_01v8_lvt sky130_fd_pr__pfet_01v8_hvt \
 		sky130_fd_pr__pfet_g5v0d10v5} full_metal 1 \
 		viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__pfet_01v8_lvt_defaults {} {
@@ -5234,7 +5439,7 @@ proc sky130::sky130_fd_pr__pfet_01v8_lvt_defaults {} {
 		sky130_fd_pr__pfet_01v8_lvt sky130_fd_pr__pfet_01v8_hvt \
 		sky130_fd_pr__pfet_g5v0d10v5} full_metal 1 \
 		viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__pfet_01v8_hvt_defaults {} {
@@ -5245,7 +5450,7 @@ proc sky130::sky130_fd_pr__pfet_01v8_hvt_defaults {} {
 		sky130_fd_pr__pfet_01v8_lvt sky130_fd_pr__pfet_01v8_hvt \
 		sky130_fd_pr__pfet_g5v0d10v5} full_metal 1 \
 		viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__pfet_g5v0d10v5_defaults {} {
@@ -5256,7 +5461,7 @@ proc sky130::sky130_fd_pr__pfet_g5v0d10v5_defaults {} {
 		sky130_fd_pr__pfet_01v8_lvt sky130_fd_pr__pfet_01v8_hvt \
 		sky130_fd_pr__pfet_g5v0d10v5} full_metal 1 \
 		viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__pfet_g5v0d16v0_defaults {} {
@@ -5264,7 +5469,7 @@ proc sky130::sky130_fd_pr__pfet_g5v0d16v0_defaults {} {
 		guard 1 glc 1 grc 1 gtc 1 gbc 1 tbcov 100 rlcov 100 \
 		topc 1 botc 1 poverlap 0 doverlap 0 lmin 1.050 wmin 5.00 \
 		class mosfet full_metal 1 viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 #----------------------------------------------------------------
@@ -5282,7 +5487,7 @@ proc sky130::sky130_fd_pr__nfet_01v8_defaults {} {
 		sky130_fd_pr__nfet_g5v0d10v5 sky130_fd_pr__nfet_05v0_nvt \
 		sky130_fd_pr__nfet_03v3_nvt} \
 		full_metal 1 viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__nfet_01v8_lvt_defaults {} {
@@ -5295,7 +5500,7 @@ proc sky130::sky130_fd_pr__nfet_01v8_lvt_defaults {} {
 		sky130_fd_pr__nfet_g5v0d10v5 sky130_fd_pr__nfet_05v0_nvt \
 		sky130_fd_pr__nfet_03v3_nvt} \
 		full_metal 1 viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_bs_flash__special_sonosfet_star_defaults {} {
@@ -5308,7 +5513,7 @@ proc sky130::sky130_fd_bs_flash__special_sonosfet_star_defaults {} {
 		sky130_fd_pr__nfet_g5v0d10v5 sky130_fd_pr__nfet_05v0_nvt \
 		sky130_fd_pr__nfet_03v3_nvt} \
 		full_metal 1 viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__nfet_g5v0d10v5_defaults {} {
@@ -5321,7 +5526,7 @@ proc sky130::sky130_fd_pr__nfet_g5v0d10v5_defaults {} {
 		sky130_fd_pr__nfet_g5v0d10v5 sky130_fd_pr__nfet_05v0_nvt \
 		sky130_fd_pr__nfet_03v3_nvt} \
 		full_metal 1 viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__nfet_05v0_nvt_defaults {} {
@@ -5334,7 +5539,7 @@ proc sky130::sky130_fd_pr__nfet_05v0_nvt_defaults {} {
 		sky130_fd_pr__nfet_g5v0d10v5 sky130_fd_pr__nfet_05v0_nvt \
 		sky130_fd_pr__nfet_03v3_nvt} \
 		full_metal 1 viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__nfet_03v3_nvt_defaults {} {
@@ -5347,7 +5552,7 @@ proc sky130::sky130_fd_pr__nfet_03v3_nvt_defaults {} {
 		sky130_fd_pr__nfet_g5v0d10v5 sky130_fd_pr__nfet_05v0_nvt \
 		sky130_fd_pr__nfet_03v3_nvt} \
 		full_metal 1 viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 proc sky130::sky130_fd_pr__nfet_g5v0d16v0_defaults {} {
@@ -5355,7 +5560,7 @@ proc sky130::sky130_fd_pr__nfet_g5v0d16v0_defaults {} {
 		guard 1 glc 1 grc 1 gtc 1 gbc 1 tbcov 100 rlcov 100 \
 		topc 1 botc 1 poverlap 0 doverlap 0 lmin 1.050 wmin 5.00 \
 		full_metal 1 viasrc 100 viadrn 100 viagate 100 \
-		viagb 0 viagr 0 viagl 0 viagt 0}
+		viagb 0 viagr 0 viagl 0 viagt 0 doports 1}
 }
 
 #----------------------------------------------------------------
@@ -5557,6 +5762,12 @@ proc sky130::mos_dialog {device parameters} {
     magic::add_entry viagt "Top guard ring via coverage \[+/-\](%)" $parameters
     magic::add_entry viagr "Right guard ring via coverage \[+/-\](%)" $parameters
     magic::add_entry viagl "Left guard ring via coverage \[+/-\](%)" $parameters
+
+    if {[dict exists $parameters addports]} {
+	magic::add_checkbox doports "Add ports" $parameters
+    }
+
+    # magic::add_checkbox dummy "Add dummy" $parameters
 }
 
 #----------------------------------------------------------------
@@ -5752,6 +5963,7 @@ proc sky130::guard_ring {gw gh parameters} {
     set plus_diff_type   nsd	;# guard ring diffusion type
     set plus_contact_type nsc	;# guard ring diffusion contact type
     set sub_type	 pwell	;# substrate type
+    set bulk ""		;# Default no port label
 
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
@@ -5799,6 +6011,7 @@ proc sky130::guard_ring {gw gh parameters} {
     popbox
     pushbox
     box move s ${hh}um
+    pushbox
     box grow n ${hdifft}um
     box grow s ${hdifft}um
     box grow e ${hdiffw}um
@@ -5809,6 +6022,13 @@ proc sky130::guard_ring {gw gh parameters} {
 	paint $guard_sub_type
     }
     popbox
+    # At guard ring bottom center, place a port if requested
+    if {$bulk != ""} {
+	label $bulk c $plus_diff_type
+	select area label
+	port make
+    }
+    popbox
     pushbox
     box move e ${hw}um
     box grow e ${hdifft}um
@@ -6201,6 +6421,7 @@ proc sky130::mos_device {parameters} {
     set eps  0.0005
 
     # Set local default values if they are not in parameters
+    set doports 0	;# no port labels by default
     set diffcov 100	;# percent coverage of diffusion contact
     set polycov 100	;# percent coverage of poly contact
     set topc 1		;# draw top poly contact
@@ -6216,6 +6437,10 @@ proc sky130::mos_device {parameters} {
     set gshield 0	;# no metal shield over gate (used for varactors)
     set drain_proc {}	;# no special procedure to draw the drain
 
+    set drain ""
+    set source ""
+    set gate ""
+
     # Set a local variable for each parameter (e.g., $l, $w, etc.)
     foreach key [dict keys $parameters] {
         set $key [dict get $parameters $key]
@@ -6353,6 +6578,7 @@ proc sky130::mos_device {parameters} {
 	dict set parameters cdwfull $cdwfull
 	dict set parameters dside $dside
 	dict set parameters sside $sside
+	dict set parameters doports $doports
 	set cext [sky130::unionbox $cext [eval $drain_proc {$parameters}]]
     } else {
 	# Drain diffusion contact
@@ -6386,6 +6612,11 @@ proc sky130::mos_device {parameters} {
 	set cext [sky130::unionbox $cext [sky130::draw_contact 0 ${cdw} \
 		${diff_surround} ${metal_surround} ${contact_size}\
 		${diff_type} ${diff_contact_type} li vert]]
+	if {$drain != ""} {
+	    label $drain c $diff_contact_type
+	    select area label
+	    port make
+	}
 	popbox
     }
 
@@ -6420,6 +6651,11 @@ proc sky130::mos_device {parameters} {
     set cext [sky130::unionbox $cext [sky130::draw_contact 0 ${cdw} \
 		${diff_surround} ${metal_surround} ${contact_size} \
 		${diff_type} ${diff_contact_type} li vert]]
+    if {$source != ""} {
+	label $source c $diff_contact_type
+	select area label
+	port make
+    }
     set diffarea $cext
     popbox
     # Gate shield (only on varactors)
@@ -6474,6 +6710,11 @@ proc sky130::mos_device {parameters} {
        set cext [sky130::unionbox $cext [sky130::draw_contact ${cpl} 0 \
 		${poly_surround} ${metal_surround} ${contact_size} \
 		${poly_type} ${poly_contact_type} li horz]]
+       if {$gate != ""} {
+	   label $gate c $poly_contact_type
+	   select area label
+	   port make
+       }
        popbox
     }
     # Bottom poly contact
@@ -6507,6 +6748,11 @@ proc sky130::mos_device {parameters} {
        set cext [sky130::unionbox $cext [sky130::draw_contact ${cpl} 0 \
 		${poly_surround} ${metal_surround} ${contact_size} \
 		${poly_type} ${poly_contact_type} li horz]]
+       if {($gate != "") && ($topc == 0)} {
+	   label $gate c $poly_contact_type
+	   select area label
+	   port make
+       }
        popbox
     }
 
@@ -6564,6 +6810,7 @@ proc sky130::mos_draw {parameters} {
     set id_surround 0	;# amount of surround on above type
     set id2_type ""	;# additional type covering everything
     set id2_surround 0	;# amount of surround on above type
+    set doports 0	;# no port labels unless requested
 
     set set_x_to_guard ""	;# override x distance to guard ring
     set set_y_to_guard ""	;# override y distance to guard ring
@@ -6724,6 +6971,7 @@ proc sky130::mos_draw {parameters} {
 	}
     }
     if {$guard != 0} {
+	if {$doports} {dict set parameters bulk B}
 	# Draw the guard ring first, as MOS well may interact with guard ring substrate
 	sky130::guard_ring $gx $gy $parameters
     }
@@ -6760,6 +7008,56 @@ proc sky130::mos_draw {parameters} {
 	    set saveeo $evenodd
 	}
         for {set yp 0} {$yp < $m} {incr yp} {
+	    # Apply rules for source/drain/gate port labeling
+	    if {$doports && ($m == 1)} {
+		if {$nf == 1} {
+		    dict set parameters drain D
+		    dict set parameters source S
+		    dict set parameters gate G
+		} else {
+		    if {$doverlap && $evens && ($xp > 0)} {
+			dict set parameters drain ""
+		    } else {
+			dict set parameters drain D$xp
+		    }
+		    if {$doverlap  && ($evens == 0) && ($xp < $nf-1)} {
+			dict set parameters source ""
+		    } else {
+			dict set parameters source S$xp
+		    }
+		    dict set parameters gate G$xp
+		}
+	    } elseif {$doports} {		
+		if {$nf == 1} {
+		    dict set parameters drain D$yp
+		    dict set parameters source S$yp
+		    if {$poverlap && ($yp == 0)} {
+			dict set parameters gate G
+		    } elseif {$poverlap} {
+			dict set parameters gate ""
+		    } else {
+			dict set parameters gate G$yp
+		    }
+		} else {
+		    if {$doverlap && $evens && ($xp > 0)} {
+			dict set parameters drain ""
+		    } else {
+			dict set parameters drain D${xp}_$yp
+		    }
+		    if {$doverlap && ($evens == 0) && ($xp < $nf-1)} {
+			dict set parameters source ""
+		    } else {
+			dict set parameters source S${xp}_$yp
+		    }
+		    if {$poverlap && ($yp == 0)} {
+			dict set parameters gate G$xp
+		    } elseif {$poverlap} {
+			dict set parameters gate ""
+		    } else {
+			dict set parameters gate G${xp}_$yp
+		    }
+		}
+	    }
             if {$evens != 0} {box move e ${xoffset}um}
             sky130::mos_device $parameters
             if {$evens != 0} {box move w ${xoffset}um}
@@ -6948,6 +7246,7 @@ proc sky130::sky130_fd_pr__nfet_g5v0d10v5_draw {parameters} {
 	    diff_spacing	0.31 \
 	    diff_tap_space	0.38 \
 	    diff_gate_space	0.38 \
+	    set_x_to_guard	0.535 \
     ]
     set drawdict [dict merge $sky130::ruleset $newdict $parameters]
     return [sky130::mos_draw $drawdict]