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Completed the first full implementation of the LDNMOS and LDPMOS
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(16V) devices in the magic tech file and device generator for
sky130.  This includes validating the device generator for
fingered devices and multiple devices, with and without
overlapping diffusions, and cifinput rules for reading the
devices from GDS and producing a valid database in magic from
which the device can again be extracted.
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@RTimothyEdwards
RTimothyEdwards committed Oct 26, 2023
1 parent 326f640 commit 392b92e
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Showing 2 changed files with 97 additions and 32 deletions.
82 changes: 51 additions & 31 deletions sky130/magic/sky130.tcl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5786,19 +5786,21 @@ proc sky130::draw_ldnmos_drain {parameters} {
box grow n ${hw}um
box grow s ${hw}um
box move $dside ${hl}um
pushbox
box grow $dside ${extension}um
paint ed
set cext [sky130::getbox]
box width 0.26um
box move $dside 0.26um
popbox
box move $dside ${extension}um
box move $dside 0.13um
box grow e 0.13um
box grow w 0.13um
paint mvnsd
# Test: Do not include nwell in bounding box
set cext [sky130::unionbox $cext [sky130::getbox]]
pushbox
box grow c 0.66um
paint nwell
# Force box 0.48um larger so that spacing to guard ring
# comes out to 0.86um.
box grow c 0.48um
set cext [sky130::unionbox $cext [sky130::getbox]]
popbox
popbox
# Back to the center point
Expand Down Expand Up @@ -5836,7 +5838,7 @@ proc sky130::draw_ldnmos_drain {parameters} {
if {$cdw > $cdwfull} [set cdw $cdwfull]

set cext [sky130::unionbox $cext [sky130::draw_contact 0 ${cdw} \
0.045 ${metal_surround} ${contact_size}\
${drain_diff_surround} ${metal_surround} ${contact_size}\
mvnsd mvnsc li vert]]
popbox
return $cext
Expand Down Expand Up @@ -5866,36 +5868,24 @@ proc sky130::draw_ldpmos_drain {parameters} {
# Starts with point at the device center
box grow n ${hw}um
box grow s ${hw}um
# Draw nwell under the entire device
pushbox
box grow e ${hl}um
box grow w ${hl}um
# Well should cover device and meet well width on
# top and bottom of the area cut out for the drain
box grow c 0.84um
box grow c 0.86um
box grow $dside ${extension}um
box grow $dside 0.26um
box grow $sside -1.08um
paint nwell
popbox
box move $dside ${hl}um
pushbox
box grow $dside ${extension}um
paint ed
set cext [sky130::getbox]
box width 0.26um
box move $dside 0.26um
popbox
box move $dside ${extension}um
box move $dside 0.13um
box grow e 0.13um
box grow w 0.13um
paint mvpsd
pushbox
box grow c 0.86um
# Shorter on gate side to avoid DRC error; actual
# Shorter than necessary to avoid DRC error; actual
# nwell is erased under gate by GDS generation rules.
box grow $sside -0.13um
box grow e -0.15um
box grow w -0.15um
paint pwell
# Force box 0.28um larger so that spacing to guard ring
# comes out to 0.66um.
box grow c 0.28um
set cext [sky130::unionbox $cext [sky130::getbox]]
popbox
popbox
# Back to the center point
Expand Down Expand Up @@ -5933,7 +5923,7 @@ proc sky130::draw_ldpmos_drain {parameters} {
if {$cdw > $cdwfull} [set cdw $cdwfull]

set cext [sky130::unionbox $cext [sky130::draw_contact 0 ${cdw} \
0.045 ${metal_surround} ${contact_size}\
${drain_diff_surround} ${metal_surround} ${contact_size}\
mvpsd mvpsc li vert]]
popbox
return $cext
Expand Down Expand Up @@ -6313,11 +6303,19 @@ proc sky130::mos_draw {parameters} {
set id2_type "" ;# additional type covering everything
set id2_surround 0 ;# amount of surround on above type

set set_x_to_guard "" ;# override x distance to guard ring
set set_y_to_guard "" ;# override y distance to guard ring

# Set a local variable for each parameter (e.g., $l, $w, etc.)
foreach key [dict keys $parameters] {
set $key [dict get $parameters $key]
}

# Diff surround on drain is by default the same as diff surround
if {![dict exist $parameters drain_diff_surround]} {
set drain_diff_surround $diff_surround
}

# Diff-to-tap spacing is by default the same as diff spacing
if {![dict exist $parameters diff_tap_space]} {
set diff_tap_space $diff_spacing
Expand Down Expand Up @@ -6361,14 +6359,18 @@ proc sky130::mos_draw {parameters} {

tech lock *
set bbox [sky130::mos_device $parameters]
# puts stdout "Diagnostic: Device bounding box e $bbox (um)"
puts stdout "Diagnostic: Device bounding box e $bbox (um)"
tech unlock *

set fw [- [lindex $bbox 2] [lindex $bbox 0]]
set fh [- [lindex $bbox 3] [lindex $bbox 1]]
set lw [+ [lindex $bbox 2] [lindex $bbox 0]]
set lh [+ [lindex $bbox 3] [lindex $bbox 1]]

# If the bounding box is not symmetric about x=0, then find the
# offset. Assumed to be needed only for X (asymmetric drain)
set xoffset [+ [lindex $bbox 0] [lindex $bbox 2]]

# If dev_sub_dist > 0 then each device must be in its own substrate
# (well) area, and overlaps are disallowed. dev_sub_space determines
# the distance between individual devices in an array.
Expand Down Expand Up @@ -6399,7 +6401,7 @@ proc sky130::mos_draw {parameters} {
set dx [+ $fw $diff_spacing]
} else {
# overlap diffusions
set dx [- $fw [+ $diff_surround $diff_surround $contact_size]]
set dx [- $fw [+ $drain_diff_surround $drain_diff_surround $contact_size]]
}
}

Expand Down Expand Up @@ -6450,6 +6452,14 @@ proc sky130::mos_draw {parameters} {
set corelly [- $corelly [/ $sdiff 2.0]]
}
}

# set_x|y_to_guard overrides the above calculations if present.
if {$set_x_to_guard != ""} {
set gx [+ $corex [* 2.0 $set_x_to_guard]]
}
if {$set_y_to_guard != ""} {
set gy [+ $corey [* 2.0 $set_y_to_guard]]
}
}
if {$guard != 0} {
# Draw the guard ring first, as MOS well may interact with guard ring substrate
Expand Down Expand Up @@ -6488,7 +6498,9 @@ proc sky130::mos_draw {parameters} {
set saveeo $evenodd
}
for {set yp 0} {$yp < $m} {incr yp} {
if {$evens != 0} {box move e ${xoffset}um}
sky130::mos_device $parameters
if {$evens != 0} {box move w ${xoffset}um}
box move n ${dy}um
if {$intc == 1} {
set evenodd [- 1 $evenodd]
Expand Down Expand Up @@ -6808,6 +6820,9 @@ proc sky130::sky130_fd_pr__nfet_g5v0d16v0_draw {parameters} {
diff_spacing 0.31 \
diff_tap_space 0.38 \
diff_gate_space 0.38 \
drain_diff_surround 0.045 \
set_x_to_guard 1.665 \
set_y_to_guard 1.225 \
drain_proc sky130::draw_ldnmos_drain \
]
set drawdict [dict merge $sky130::ruleset $newdict $parameters]
Expand All @@ -6824,11 +6839,16 @@ proc sky130::sky130_fd_pr__pfet_g5v0d16v0_draw {parameters} {
poly_type poly \
poly_contact_type pc \
sub_type nwell \
id_type nwell \
id_surround 0.035 \
guard_sub_surround 0.33 \
gate_to_polycont 0.32 \
diff_spacing 0.31 \
diff_tap_space 0.38 \
diff_gate_space 0.38 \
drain_diff_surround 0.045 \
set_x_to_guard 1.665 \
set_y_to_guard 1.180 \
drain_proc sky130::draw_ldpmos_drain \
]
set drawdict [dict merge $sky130::ruleset $newdict $parameters]
Expand Down
47 changes: 46 additions & 1 deletion sky130/magic/sky130.tech
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1136,7 +1136,9 @@ style gdsii
# HVI (includes rules NWELL 8-11 and DIFFTAP 14-26)
#----------------------------------------------------------------

templayer thkox_area alldiffmv,mvvar
templayer thkox_area ed
grow 475
or alldiffmv,mvvar
grow 185
bloat-all alldiffmv nwell
grow 345
Expand Down Expand Up @@ -2987,6 +2989,47 @@ style sky130 variants (),(vendor)
labels TAP
labels TAPTXT text

# Fill in FET under extended drain
layer mvpfet EDID
and POLY
and-not DIFF
and-not TAP
and-not NWELL

layer mvnfet EDID
and POLY
and-not DIFF
and-not TAP
and NWELL

# Restrict where nwell is merged
templayer ldmos_nwell EDID
grow 1200
and NWELL

# Remove or add well under extended FET gate
layer nwell EDID
and POLY
and DIFF
and PSDM
grow 685
or ldmos_nwell
grow 420
shrink 420

layer pwell EDID
and POLY
and DIFF
and NSDM
grow 660
grow 420
shrink 420

layer ed EDID
and-not POLY
and-not DIFF
and-not TAP

templayer mvnsdexpand mvnsdarea
grow 500

Expand Down Expand Up @@ -3977,6 +4020,8 @@ style sky130 variants (),(vendor)
calma PSDM 94 20
# HVI (THKOX)
calma HVI 75 20
# EDID
calma EDID 81 57
# NPC
calma NPC 95 20
# P+ POLY MASK
Expand Down

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