ASIC Point

Pin placement

Put a block's I/O pins on the die edge on purpose: know which layer each edge uses, how the flow places pins from the cells, and what a poor plan costs in wirelength.

Lesson
L3.2
Time
25 min
Runs on
OpenROAD
Check
5 questions

A flow placed the MAC's 39 pins before any cell had a position. With nothing to aim at, all 39 pins went onto the left edge. The placed wirelength came out 21.9 % longer than with pins placed after the cells.

LayoutThe MAC with its pins placed before its cellsEvery pin is on the left edge, and the logic crowds toward it.
  • Tap cells
  • Logic
  • Buffers and inverters
  • Flip-flops
  • Power stripes
  • I/O pins
Stage
Detailed placement
Cell area
4,332.9 µm²
Utilization
42.4 %
Wirelength (HPWL)
7,365 µm
Worst max slack
4.9184 ns
Total negative max slack
0.0000 ns
Worst min slack
0.4641 ns
The MAC with its pins placed before its cellsDrawing the layout…
  1. Pins first

    place_pins runs on an empty core. No cell has a position yet, so the tool has nothing to aim at and puts all 39 pins on the left edge.

  2. Cells follow

    The placer pulls each cell toward its pins, so the logic piles up near the left edge. Placed wirelength: 7365 µm.

Read the layout as text

mac: die 112.02 × 112.02 µm, core 101.66 × 100.64 µm, 37 rows of 2.72 µm, 39 signal pins.

StageCell areaUtilizationWirelength (HPWL)Worst max slackTotal negative max slackWorst min slackOverflowCells placed
Floorplan4,332.9 µm²42.4 %—5.7041 ns0.0000 ns0.4243 ns—136 tap cells
Global placement4,332.9 µm²42.4 %6,231 µm5.0296 ns0.0000 ns0.4573 ns0.0991136 tap cells, 6 buffers and inverters, 389 logic, 52 flip-flops
Detailed placement4,332.9 µm²42.4 %7,365 µm4.9184 ns0.0000 ns0.4641 ns—136 tap cells, 6 buffers and inverters, 389 logic, 52 flip-flops

The flow's floorplan and placement steps with place_pins moved before global placement (OpenROAD 26Q2, sky130hd).

A pin's position decides where the cells behind it go.

Pins, edges and layers

An I/O pin is a small metal shape on the die boundary where a net leaves the block. The MAC has 39: clk, rst_n, en, the inputs a[7:0] and b[7:0], and the output acc[19:0].

place_pins -hor_layers met3 -ver_layers met2 names one layer for each kind of edge. A pin on the left or right edge is reached by a wire running sideways, so it sits on a horizontal layer, met3. A pin on the top or bottom edge sits on a vertical layer, met2. This platform sets the two layers in its configuration (IO_PLACER_H, IO_PLACER_V).

EdgePinsLayerPreferred direction
left12met3horizontal
right10met3horizontal
bottom10met2vertical
top7met2vertical

The pins of the flow's own plan below, counted by edge from the run.

Pins also sit on routing tracks of their layer, with a minimum spacing between them, and the tool keeps them away from the corners.

Placing pins from the cells

The flow solves a chicken-and-egg problem. Good pin positions depend on where the cells are, and good cell positions depend on where the pins are. It breaks the loop in three steps.

  1. Place without pins

    global_placement -skip_io spreads the cells while ignoring the I/O nets.

  2. Place the pins

    place_pins assigns pins to legal slots to reduce estimated wirelength to their connected cells, subject to spacing and edge constraints.

  3. Place again

    global_placement runs once more with the pins fixed, so the cells settle toward them.

LayoutThe MAC with its pins placed from the cellsThe flow's own plan: 12 left, 10 right, 10 bottom, 7 top.
  • Tap cells
  • Logic
  • Buffers and inverters
  • Flip-flops
  • Power stripes
  • I/O pins
Stage
Detailed placement
Cell area
4,332.9 µm²
Utilization
42.4 %
Wirelength (HPWL)
6,041 µm
Worst max slack
5.1639 ns
Total negative max slack
0.0000 ns
Worst min slack
0.4534 ns
The MAC with its pins placed from the cellsDrawing the layout…
  1. No pins yet

    The floorplan has rows, taps and the power grid, and no pins.

  2. Pins near their cells

    After the two placements every edge carries pins: 12 left, 10 right, 10 bottom, 7 top. Placed wirelength 4952 µm before legalization.

  3. Legalized

    After detailed placement: 6041 µm, 1324 µm less than with every pin on the left.

Read the layout as text

mac: die 112.02 × 112.02 µm, core 101.66 × 100.64 µm, 37 rows of 2.72 µm, 39 signal pins.

StageCell areaUtilizationWirelength (HPWL)Worst max slackTotal negative max slackWorst min slackOverflowCells placed
Floorplan4,332.9 µm²42.4 %—5.7041 ns0.0000 ns0.4243 ns—136 tap cells; I/O pins not placed yet
Global placement4,332.9 µm²42.4 %4,952 µm5.2629 ns0.0000 ns0.4496 ns0.0994136 tap cells, 6 buffers and inverters, 389 logic, 52 flip-flops
Detailed placement4,332.9 µm²42.4 %6,041 µm5.1639 ns0.0000 ns0.4534 ns—136 tap cells, 6 buffers and inverters, 389 logic, 52 flip-flops

Measured with OpenROAD 26Q2 on sky130hd at 40 % utilization.

HPWL, the half-perimeter wirelength, estimates a net's wire as half the perimeter of the box around its pins. Summed over all nets it is the placer's measure of wirelength. It is an estimate: the routed wires come later (L6).

Why does a pin move the cells at all? The placer minimizes total wirelength, and a fixed pin is one end of every net it drives. Each cell on such a net feels a pull toward that pin, and so does every cell connected to those cells. A pin is an anchor for the whole cone of logic behind it, not only for the first gate.

Pins as an agreement

Inside a larger chip, a block's pins must face the blocks they talk to. The top-level designer and the block designer agree the edges first. The tool then follows constraints: set_io_pin_constraint -pin_names {a[*]} -region left:* keeps the bus a on the left edge. A region can also be a stretch of an edge, such as bottom:10-50 in µm. -group keeps the listed pins together, and adding -order preserves their listed order along the edge.

Here is the same MAC with two constrained plans, beside the two above:

Pin planPins per edgePlaced HPWLHPWL of the I/O netsWNS
From the cells (the flow's own)12 left, 10 right, 10 bottom, 7 top6041 µm1407 µm5.1639 ns
a and b at the bottom, acc at the top3 left, 16 bottom, 20 top6853 µm1742 µm5.1443 ns
a and acc left, b right31 left, 8 right7295 µm1802 µm5.1187 ns
Before the cells39 left7365 µm1982 µm4.9184 ns

After detailed placement, with wire parasitics estimated from the placement and a 10 ns clock. Each plan is a run of the same flow with its own pin step.

Splitting a and b onto opposite edges costs 20.7 %. The multiplier needs both operands at once, so its cells stretch across the core between them. Only 394 µm of the 1253 µm extra is on the I/O nets themselves. The rest is internal wiring, stretched toward the misplaced pins.

LayoutThe MAC with a on the left and b on the rightThe multiplier's cells stretch between the two operand buses.
  • Tap cells
  • Logic
  • Buffers and inverters
  • Flip-flops
  • I/O pins
Stage
Detailed placement
Cell area
4,332.9 µm²
Utilization
42.4 %
Wirelength (HPWL)
7,295 µm
Worst max slack
5.1187 ns
Total negative max slack
0.0000 ns
Worst min slack
0.4671 ns
The MAC with a on the left and b on the rightDrawing the layout…
  1. Pulled two ways

    31 left, 8 right: placed wirelength 7295 µm.

Read the layout as text

mac: die 112.02 × 112.02 µm, core 101.66 × 100.64 µm, 37 rows of 2.72 µm, 39 signal pins.

StageCell areaUtilizationWirelength (HPWL)Worst max slackTotal negative max slackWorst min slackOverflowCells placed
Floorplan4,332.9 µm²42.4 %—5.7041 ns0.0000 ns0.4243 ns—136 tap cells
Global placement4,332.9 µm²42.4 %6,085 µm5.1954 ns0.0000 ns0.4561 ns0.0995136 tap cells, 6 buffers and inverters, 389 logic, 52 flip-flops
Detailed placement4,332.9 µm²42.4 %7,295 µm5.1187 ns0.0000 ns0.4671 ns—136 tap cells, 6 buffers and inverters, 389 logic, 52 flip-flops

The same flow with set_io_pin_constraint before place_pins (OpenROAD 26Q2, sky130hd).

With the chosen 10 ns constraint the two slacks are 5.1187 against 5.1639 ns. Wire delay depends on the route and load, not the clock period; a similar delay change matters more when the timing margin is smaller. At the top level the cost of a bad plan is wire outside the block: a bus that enters on the wrong side crosses the block in top-level wiring.

Asked in interviews

  1. How do you decide where a block's pins go?

    From the top-level floorplan: each bus faces the block it connects to, agreed with the top-level designer. Inside those limits the tool places pins near the cells that use them.

  2. What happens if pins are placed badly?

    The placer pulls the logic toward the pins, so internal wires stretch, and the top level must route around the block. Wirelength can grow, increasing congestion or delay; the run measures the actual trade-off.

  3. How does the tool place pins automatically?

    It first places cells without the I/O, assigns pins to legal slots using estimated wirelength, then places cells again with the pins fixed.

  4. Why does a pin on the left edge use a horizontal layer?

    The wire that reaches it runs horizontally, so the pin is on a layer whose preferred direction is horizontal (met3 here).

Try it

Run the MAC through placement. In Layout, step from the floorplan, which has no pins, to global placement, where every edge carries some. "Read the layout as text" lists each pin with its layer.

Now set the aspect ratio to 4. The core gets tall and narrow; watch which edges the pins move to and how the placed wirelength changes.

FLOWOpenROAD 26Q2 · sky130hd · simulator service
Edit the constraints, then run them

          

        
Expected: global placement HPWL 4951.9665 µm detailed placement HPWL 6041.2405 µm

        
        
      
Read the netlist: mac.v (the bundled design mac8)
/* Generated by Yosys 0.70+290 (git sha1 e8968a4f7, Release, Clang /usr/bin/clang++ 21.1.8) */

module mac(clk, rst_n, en, a, b, acc);
  input clk;
  wire clk;
  input rst_n;
  wire rst_n;
  input en;
  wire en;
  input [7:0] a;
  wire [7:0] a;
  input [7:0] b;
  wire [7:0] b;
  output [19:0] acc;
  wire [19:0] acc;
  wire _000_;
  wire _001_;
  wire _002_;
  wire _003_;
  wire _004_;
  wire _005_;
  wire _006_;
  wire _007_;
  wire _008_;
  wire _009_;
  wire _010_;
  wire _011_;
  wire _012_;
  wire _013_;
  wire _014_;
  wire _015_;
  wire _016_;
  wire _017_;
  wire _018_;
  wire _019_;
  wire _020_;
  wire _021_;
  wire _022_;
  wire _023_;
  wire _024_;
  wire _025_;
  wire _026_;
  wire _027_;
  wire _028_;
  wire _029_;
  wire _030_;
  wire _031_;
  wire _032_;
  wire _033_;
  wire _034_;
  wire _035_;
  wire _036_;
  wire _037_;
  wire _038_;
  wire _039_;
  wire _040_;
  wire _041_;
  wire _042_;
  wire _043_;
  wire _044_;
  wire _045_;
  wire _046_;
  wire _047_;
  wire _048_;
  wire _049_;
  wire _050_;
  wire _051_;
  wire _052_;
  wire _053_;
  wire _054_;
  wire _055_;
  wire _056_;
  wire _057_;
  wire _058_;
  wire _059_;
  wire _060_;
  wire _061_;
  wire _062_;
  wire _063_;
  wire _064_;
  wire _065_;
  wire _066_;
  wire _067_;
  wire _068_;
  wire _069_;
  wire _070_;
  wire _071_;
  wire _072_;
  wire _073_;
  wire _074_;
  wire _075_;
  wire _076_;
  wire _077_;
  wire _078_;
  wire _079_;
  wire _080_;
  wire _081_;
  wire _082_;
  wire _083_;
  wire _084_;
  wire _085_;
  wire _086_;
  wire _087_;
  wire _088_;
  wire _089_;
  wire _090_;
  wire _091_;
  wire _092_;
  wire _093_;
  wire _094_;
  wire _095_;
  wire _096_;
  wire _097_;
  wire _098_;
  wire _099_;
  wire _100_;
  wire _101_;
  wire _102_;
  wire _103_;
  wire _104_;
  wire _105_;
  wire _106_;
  wire _107_;
  wire _108_;
  wire _109_;
  wire _110_;
  wire _111_;
  wire _112_;
  wire _113_;
  wire _114_;
  wire _115_;
  wire _116_;
  wire _117_;
  wire _118_;
  wire _119_;
  wire _120_;
  wire _121_;
  wire _122_;
  wire _123_;
  wire _124_;
  wire _125_;
  wire _126_;
  wire _127_;
  wire _128_;
  wire _129_;
  wire _130_;
  wire _131_;
  wire _132_;
  wire _133_;
  wire _134_;
  wire _135_;
  wire _136_;
  wire _137_;
  wire _138_;
  wire _139_;
  wire _140_;
  wire _141_;
  wire _142_;
  wire _143_;
  wire _144_;
  wire _145_;
  wire _146_;
  wire _147_;
  wire _148_;
  wire _149_;
  wire _150_;
  wire _151_;
  wire _152_;
  wire _153_;
  wire _154_;
  wire _155_;
  wire _156_;
  wire _157_;
  wire _158_;
  wire _159_;
  wire _160_;
  wire _161_;
  wire _162_;
  wire _163_;
  wire _164_;
  wire _165_;
  wire _166_;
  wire _167_;
  wire _168_;
  wire _169_;
  wire _170_;
  wire _171_;
  wire _172_;
  wire _173_;
  wire _174_;
  wire _175_;
  wire _176_;
  wire _177_;
  wire _178_;
  wire _179_;
  wire _180_;
  wire _181_;
  wire _182_;
  wire _183_;
  wire _184_;
  wire _185_;
  wire _186_;
  wire _187_;
  wire _188_;
  wire _189_;
  wire _190_;
  wire _191_;
  wire _192_;
  wire _193_;
  wire _194_;
  wire _195_;
  wire _196_;
  wire _197_;
  wire _198_;
  wire _199_;
  wire _200_;
  wire _201_;
  wire _202_;
  wire _203_;
  wire _204_;
  wire _205_;
  wire _206_;
  wire _207_;
  wire _208_;
  wire _209_;
  wire _210_;
  wire _211_;
  wire _212_;
  wire _213_;
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  wire _215_;
  wire _216_;
  wire _217_;
  wire _218_;
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  wire _235_;
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  wire _245_;
  wire _246_;
  wire _247_;
  wire _248_;
  wire _249_;
  wire _250_;
  wire _251_;
  wire _252_;
  wire _253_;
  wire _254_;
  wire _255_;
  wire _256_;
  wire _257_;
  wire _258_;
  wire _259_;
  wire _260_;
  wire _261_;
  wire _262_;
  wire _263_;
  wire _264_;
  wire _265_;
  wire _266_;
  wire _267_;
  wire _268_;
  wire _269_;
  wire _270_;
  wire _271_;
  wire _272_;
  wire _273_;
  wire _274_;
  wire _275_;
  wire _276_;
  wire _277_;
  wire _278_;
  wire _279_;
  wire _280_;
  wire _281_;
  wire _282_;
  wire _283_;
  wire _284_;
  wire _285_;
  wire _286_;
  wire _287_;
  wire _288_;
  wire _289_;
  wire _290_;
  wire _291_;
  wire _292_;
  wire _293_;
  wire _294_;
  wire _295_;
  wire _296_;
  wire _297_;
  wire _298_;
  wire _299_;
  wire _300_;
  wire _301_;
  wire _302_;
  wire _303_;
  wire _304_;
  wire _305_;
  wire _306_;
  wire _307_;
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  wire _309_;
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  wire _313_;
  wire _314_;
  wire _315_;
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  wire _318_;
  wire _319_;
  wire _320_;
  wire _321_;
  wire _322_;
  wire _323_;
  wire _324_;
  wire _325_;
  wire _326_;
  wire _327_;
  wire _328_;
  wire _329_;
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  wire _332_;
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  wire _335_;
  wire _336_;
  wire _337_;
  wire _338_;
  wire _339_;
  wire _340_;
  wire _341_;
  wire _342_;
  wire _343_;
  wire _344_;
  wire _345_;
  wire _346_;
  wire _347_;
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  wire _349_;
  wire _350_;
  wire _351_;
  wire _352_;
  wire _353_;
  wire _354_;
  wire _355_;
  wire _356_;
  wire _357_;
  wire _358_;
  wire _359_;
  wire _360_;
  wire _361_;
  wire _362_;
  wire _363_;
  wire _364_;
  wire _365_;
  wire _366_;
  wire _367_;
  wire _368_;
  wire _369_;
  wire _370_;
  wire _371_;
  wire _372_;
  wire _373_;
  wire _374_;
  wire _375_;
  wire _376_;
  wire _377_;
  wire _378_;
  wire _379_;
  wire _380_;
  wire _381_;
  wire _382_;
  wire _383_;
  wire _384_;
  wire _385_;
  wire _386_;
  wire _387_;
  wire _388_;
  wire _389_;
  wire _390_;
  wire _391_;
  wire _392_;
  wire _393_;
  wire _394_;
  wire \p[0] ;
  wire \p[10] ;
  wire \p[11] ;
  wire \p[12] ;
  wire \p[13] ;
  wire \p[14] ;
  wire \p[15] ;
  wire \p[1] ;
  wire \p[2] ;
  wire \p[3] ;
  wire \p[4] ;
  wire \p[5] ;
  wire \p[6] ;
  wire \p[7] ;
  wire \p[8] ;
  wire \p[9] ;
  wire \ra[0] ;
  wire \ra[1] ;
  wire \ra[2] ;
  wire \ra[3] ;
  wire \ra[4] ;
  wire \ra[5] ;
  wire \ra[6] ;
  wire \ra[7] ;
  wire \rb[0] ;
  wire \rb[1] ;
  wire \rb[2] ;
  wire \rb[3] ;
  wire \rb[4] ;
  wire \rb[5] ;
  wire \rb[6] ;
  wire \rb[7] ;
  sky130_fd_sc_hd__clkinv_1 _395_ (
    .A(en),
    .Y(_052_)
  );
  sky130_fd_sc_hd__clkinv_1 _396_ (
    .A(acc[16]),
    .Y(_053_)
  );
  sky130_fd_sc_hd__xnor2_1 _397_ (
    .A(acc[12]),
    .B(\p[12] ),
    .Y(_061_)
  );
  sky130_fd_sc_hd__xor3_1 _398_ (
    .A(_112_),
    .B(_145_),
    .C(_146_),
    .X(_148_)
  );
  sky130_fd_sc_hd__nand2_1 _399_ (
    .A(_144_),
    .B(_148_),
    .Y(_149_)
  );
  sky130_fd_sc_hd__nand3_1 _400_ (
    .A(\ra[7] ),
    .B(\rb[2] ),
    .C(_149_),
    .Y(_150_)
  );
  sky130_fd_sc_hd__xnor2_1 _401_ (
    .A(_115_),
    .B(_116_),
    .Y(_151_)
  );
  sky130_fd_sc_hd__nand2_1 _402_ (
    .A(\rb[7] ),
    .B(\ra[3] ),
    .Y(_152_)
  );
  sky130_fd_sc_hd__maj3_1 _403_ (
    .A(_112_),
    .B(_145_),
    .C(_146_),
    .X(_153_)
  );
  sky130_fd_sc_hd__nand2_1 _404_ (
    .A(\ra[4] ),
    .B(\rb[6] ),
    .Y(_154_)
  );
  sky130_fd_sc_hd__xnor2_1 _405_ (
    .A(_153_),
    .B(_154_),
    .Y(_155_)
  );
  sky130_fd_sc_hd__xnor2_1 _406_ (
    .A(_152_),
    .B(_155_),
    .Y(_156_)
  );
  sky130_fd_sc_hd__maj3_1 _407_ (
    .A(_150_),
    .B(_151_),
    .C(_156_),
    .X(_157_)
  );
  sky130_fd_sc_hd__clkinv_1 _408_ (
    .A(_061_),
    .Y(_062_)
  );
  sky130_fd_sc_hd__xnor2_1 _409_ (
    .A(_120_),
    .B(_124_),
    .Y(_158_)
  );
  sky130_fd_sc_hd__nor2b_1 _410_ (
    .A(_157_),
    .B_N(_158_),
    .Y(_159_)
  );
  sky130_fd_sc_hd__maj3_1 _411_ (
    .A(_152_),
    .B(_153_),
    .C(_154_),
    .X(_160_)
  );
  sky130_fd_sc_hd__xnor2_1 _412_ (
    .A(_157_),
    .B(_158_),
    .Y(_161_)
  );
  sky130_fd_sc_hd__nor2b_1 _413_ (
    .A(_160_),
    .B_N(_161_),
    .Y(_162_)
  );
  sky130_fd_sc_hd__xor2_1 _414_ (
    .A(_135_),
    .B(_136_),
    .X(_163_)
  );
  sky130_fd_sc_hd__o21a_1 _415_ (
    .A1(_159_),
    .A2(_162_),
    .B1(_163_),
    .X(_164_)
  );
  sky130_fd_sc_hd__nand2_1 _416_ (
    .A(\ra[7] ),
    .B(\rb[1] ),
    .Y(_165_)
  );
  sky130_fd_sc_hd__and2_0 _417_ (
    .A(\ra[6] ),
    .B(\rb[0] ),
    .X(_166_)
  );
  sky130_fd_sc_hd__nand2_1 _418_ (
    .A(\ra[7] ),
    .B(\rb[0] ),
    .Y(_167_)
  );
  sky130_fd_sc_hd__and2_0 _419_ (
    .A(acc[11]),
    .B(\p[11] ),
    .X(_063_)
  );
  sky130_fd_sc_hd__nand2_1 _420_ (
    .A(\ra[5] ),
    .B(\rb[2] ),
    .Y(_168_)
  );
  sky130_fd_sc_hd__maj3_1 _421_ (
    .A(_144_),
    .B(_167_),
    .C(_168_),
    .X(_169_)
  );
  sky130_fd_sc_hd__nand2_1 _422_ (
    .A(\ra[6] ),
    .B(\rb[2] ),
    .Y(_170_)
  );
  sky130_fd_sc_hd__xnor2_1 _423_ (
    .A(_165_),
    .B(_170_),
    .Y(_171_)
  );
  sky130_fd_sc_hd__nand2_1 _424_ (
    .A(\ra[3] ),
    .B(\rb[5] ),
    .Y(_172_)
  );
  sky130_fd_sc_hd__nand2_1 _425_ (
    .A(\ra[4] ),
    .B(\rb[4] ),
    .Y(_173_)
  );
  sky130_fd_sc_hd__nand2_1 _426_ (
    .A(\ra[4] ),
    .B(\rb[3] ),
    .Y(_174_)
  );
  sky130_fd_sc_hd__xor3_1 _427_ (
    .A(_147_),
    .B(_172_),
    .C(_173_),
    .X(_175_)
  );
  sky130_fd_sc_hd__maj3_1 _428_ (
    .A(_169_),
    .B(_171_),
    .C(_175_),
    .X(_176_)
  );
  sky130_fd_sc_hd__nand3_1 _429_ (
    .A(\ra[7] ),
    .B(\rb[2] ),
    .C(_144_),
    .Y(_177_)
  );
  sky130_fd_sc_hd__nand2_1 _430_ (
    .A(acc[11]),
    .B(\p[11] ),
    .Y(_064_)
  );
  sky130_fd_sc_hd__xnor2_1 _431_ (
    .A(_148_),
    .B(_177_),
    .Y(_178_)
  );
  sky130_fd_sc_hd__nand2_1 _432_ (
    .A(\rb[7] ),
    .B(\ra[2] ),
    .Y(_179_)
  );
  sky130_fd_sc_hd__maj3_1 _433_ (
    .A(_147_),
    .B(_172_),
    .C(_173_),
    .X(_180_)
  );
  sky130_fd_sc_hd__nand2_1 _434_ (
    .A(\ra[3] ),
    .B(\rb[6] ),
    .Y(_181_)
  );
  sky130_fd_sc_hd__xnor2_1 _435_ (
    .A(_180_),
    .B(_181_),
    .Y(_182_)
  );
  sky130_fd_sc_hd__xnor2_1 _436_ (
    .A(_179_),
    .B(_182_),
    .Y(_183_)
  );
  sky130_fd_sc_hd__xnor2_1 _437_ (
    .A(_176_),
    .B(_178_),
    .Y(_184_)
  );
  sky130_fd_sc_hd__maj3_1 _438_ (
    .A(_176_),
    .B(_178_),
    .C(_183_),
    .X(_185_)
  );
  sky130_fd_sc_hd__xor3_1 _439_ (
    .A(_150_),
    .B(_151_),
    .C(_156_),
    .X(_186_)
  );
  sky130_fd_sc_hd__maj3_1 _440_ (
    .A(_179_),
    .B(_180_),
    .C(_181_),
    .X(_187_)
  );
  sky130_fd_sc_hd__nor2_1 _441_ (
    .A(acc[11]),
    .B(\p[11] ),
    .Y(_065_)
  );
  sky130_fd_sc_hd__xor2_1 _442_ (
    .A(_185_),
    .B(_186_),
    .X(_188_)
  );
  sky130_fd_sc_hd__maj3_1 _443_ (
    .A(_185_),
    .B(_186_),
    .C(_187_),
    .X(_189_)
  );
  sky130_fd_sc_hd__xor2_1 _444_ (
    .A(_160_),
    .B(_161_),
    .X(_190_)
  );
  sky130_fd_sc_hd__nor2_1 _445_ (
    .A(_189_),
    .B(_190_),
    .Y(_191_)
  );
  sky130_fd_sc_hd__nand2_1 _446_ (
    .A(\ra[5] ),
    .B(\rb[0] ),
    .Y(_192_)
  );
  sky130_fd_sc_hd__and2_0 _447_ (
    .A(\ra[5] ),
    .B(\rb[1] ),
    .X(_193_)
  );
  sky130_fd_sc_hd__and2_0 _448_ (
    .A(\ra[4] ),
    .B(\rb[2] ),
    .X(_194_)
  );
  sky130_fd_sc_hd__maj3_1 _449_ (
    .A(_166_),
    .B(_193_),
    .C(_194_),
    .X(_195_)
  );
  sky130_fd_sc_hd__xnor3_1 _450_ (
    .A(_144_),
    .B(_167_),
    .C(_168_),
    .X(_196_)
  );
  sky130_fd_sc_hd__nand2_1 _451_ (
    .A(\ra[2] ),
    .B(\rb[5] ),
    .Y(_197_)
  );
  sky130_fd_sc_hd__clkinv_1 _452_ (
    .A(_065_),
    .Y(_066_)
  );
  sky130_fd_sc_hd__nand2_1 _453_ (
    .A(\ra[3] ),
    .B(\rb[4] ),
    .Y(_198_)
  );
  sky130_fd_sc_hd__nand2_1 _454_ (
    .A(\ra[3] ),
    .B(\rb[3] ),
    .Y(_199_)
  );
  sky130_fd_sc_hd__xnor3_1 _455_ (
    .A(_174_),
    .B(_197_),
    .C(_198_),
    .X(_200_)
  );
  sky130_fd_sc_hd__maj3_1 _456_ (
    .A(_195_),
    .B(_196_),
    .C(_200_),
    .X(_201_)
  );
  sky130_fd_sc_hd__xnor3_1 _457_ (
    .A(_169_),
    .B(_171_),
    .C(_175_),
    .X(_202_)
  );
  sky130_fd_sc_hd__nand2_1 _458_ (
    .A(\rb[7] ),
    .B(\ra[1] ),
    .Y(_203_)
  );
  sky130_fd_sc_hd__maj3_1 _459_ (
    .A(_174_),
    .B(_197_),
    .C(_198_),
    .X(_204_)
  );
  sky130_fd_sc_hd__nand2_1 _460_ (
    .A(\ra[2] ),
    .B(\rb[6] ),
    .Y(_205_)
  );
  sky130_fd_sc_hd__xor2_1 _461_ (
    .A(_204_),
    .B(_205_),
    .X(_206_)
  );
  sky130_fd_sc_hd__xnor2_1 _462_ (
    .A(_203_),
    .B(_206_),
    .Y(_207_)
  );
  sky130_fd_sc_hd__and2_0 _463_ (
    .A(acc[10]),
    .B(\p[10] ),
    .X(_067_)
  );
  sky130_fd_sc_hd__xor2_1 _464_ (
    .A(_201_),
    .B(_202_),
    .X(_208_)
  );
  sky130_fd_sc_hd__maj3_1 _465_ (
    .A(_201_),
    .B(_202_),
    .C(_207_),
    .X(_209_)
  );
  sky130_fd_sc_hd__xnor2_1 _466_ (
    .A(_183_),
    .B(_184_),
    .Y(_210_)
  );
  sky130_fd_sc_hd__nand2b_1 _467_ (
    .A_N(_210_),
    .B(_209_),
    .Y(_211_)
  );
  sky130_fd_sc_hd__maj3_1 _468_ (
    .A(_203_),
    .B(_204_),
    .C(_205_),
    .X(_212_)
  );
  sky130_fd_sc_hd__xnor2_1 _469_ (
    .A(_209_),
    .B(_210_),
    .Y(_213_)
  );
  sky130_fd_sc_hd__nand2b_1 _470_ (
    .A_N(_212_),
    .B(_213_),
    .Y(_214_)
  );
  sky130_fd_sc_hd__and2_0 _471_ (
    .A(_211_),
    .B(_214_),
    .X(_215_)
  );
  sky130_fd_sc_hd__xor2_1 _472_ (
    .A(_187_),
    .B(_188_),
    .X(_216_)
  );
  sky130_fd_sc_hd__nor2_1 _473_ (
    .A(_215_),
    .B(_216_),
    .Y(_217_)
  );
  sky130_fd_sc_hd__nor2_1 _474_ (
    .A(acc[10]),
    .B(\p[10] ),
    .Y(_068_)
  );
  sky130_fd_sc_hd__nand2_1 _475_ (
    .A(\ra[4] ),
    .B(\rb[1] ),
    .Y(_218_)
  );
  sky130_fd_sc_hd__and2_0 _476_ (
    .A(\ra[4] ),
    .B(\rb[0] ),
    .X(_219_)
  );
  sky130_fd_sc_hd__nand2_1 _477_ (
    .A(\ra[3] ),
    .B(\rb[2] ),
    .Y(_220_)
  );
  sky130_fd_sc_hd__maj3_1 _478_ (
    .A(_192_),
    .B(_218_),
    .C(_220_),
    .X(_221_)
  );
  sky130_fd_sc_hd__xnor3_1 _479_ (
    .A(_166_),
    .B(_193_),
    .C(_194_),
    .X(_222_)
  );
  sky130_fd_sc_hd__nand2_1 _480_ (
    .A(\ra[1] ),
    .B(\rb[5] ),
    .Y(_223_)
  );
  sky130_fd_sc_hd__nand2_1 _481_ (
    .A(\ra[2] ),
    .B(\rb[4] ),
    .Y(_224_)
  );
  sky130_fd_sc_hd__nand2_1 _482_ (
    .A(\ra[2] ),
    .B(\rb[3] ),
    .Y(_225_)
  );
  sky130_fd_sc_hd__xor3_1 _483_ (
    .A(_199_),
    .B(_223_),
    .C(_224_),
    .X(_226_)
  );
  sky130_fd_sc_hd__maj3_1 _484_ (
    .A(_221_),
    .B(_222_),
    .C(_226_),
    .X(_227_)
  );
  sky130_fd_sc_hd__nor2_1 _485_ (
    .A(_067_),
    .B(_068_),
    .Y(_069_)
  );
  sky130_fd_sc_hd__xnor3_1 _486_ (
    .A(_195_),
    .B(_196_),
    .C(_200_),
    .X(_228_)
  );
  sky130_fd_sc_hd__nand2_1 _487_ (
    .A(\rb[7] ),
    .B(\ra[0] ),
    .Y(_229_)
  );
  sky130_fd_sc_hd__maj3_1 _488_ (
    .A(_199_),
    .B(_223_),
    .C(_224_),
    .X(_230_)
  );
  sky130_fd_sc_hd__nand2_1 _489_ (
    .A(\ra[1] ),
    .B(\rb[6] ),
    .Y(_231_)
  );
  sky130_fd_sc_hd__xor3_1 _490_ (
    .A(_229_),
    .B(_230_),
    .C(_231_),
    .X(_232_)
  );
  sky130_fd_sc_hd__xnor2_1 _491_ (
    .A(_227_),
    .B(_228_),
    .Y(_233_)
  );
  sky130_fd_sc_hd__maj3_1 _492_ (
    .A(_227_),
    .B(_228_),
    .C(_232_),
    .X(_234_)
  );
  sky130_fd_sc_hd__xnor2_1 _493_ (
    .A(_207_),
    .B(_208_),
    .Y(_235_)
  );
  sky130_fd_sc_hd__nor2_1 _494_ (
    .A(_234_),
    .B(_235_),
    .Y(_236_)
  );
  sky130_fd_sc_hd__maj3_1 _495_ (
    .A(_229_),
    .B(_230_),
    .C(_231_),
    .X(_237_)
  );
  sky130_fd_sc_hd__and2_0 _496_ (
    .A(acc[9]),
    .B(\p[9] ),
    .X(_070_)
  );
  sky130_fd_sc_hd__xor3_1 _497_ (
    .A(_207_),
    .B(_208_),
    .C(_234_),
    .X(_238_)
  );
  sky130_fd_sc_hd__nor2_1 _498_ (
    .A(_237_),
    .B(_238_),
    .Y(_239_)
  );
  sky130_fd_sc_hd__nor2_1 _499_ (
    .A(_236_),
    .B(_239_),
    .Y(_240_)
  );
  sky130_fd_sc_hd__xnor2_1 _500_ (
    .A(_212_),
    .B(_213_),
    .Y(_241_)
  );
  sky130_fd_sc_hd__o21ai_0 _501_ (
    .A1(_236_),
    .A2(_239_),
    .B1(_241_),
    .Y(_242_)
  );
  sky130_fd_sc_hd__and2_0 _502_ (
    .A(\ra[3] ),
    .B(\rb[1] ),
    .X(_243_)
  );
  sky130_fd_sc_hd__nand2_1 _503_ (
    .A(\ra[3] ),
    .B(\rb[0] ),
    .Y(_244_)
  );
  sky130_fd_sc_hd__and2_0 _504_ (
    .A(\ra[2] ),
    .B(\rb[2] ),
    .X(_245_)
  );
  sky130_fd_sc_hd__maj3_1 _505_ (
    .A(_219_),
    .B(_243_),
    .C(_245_),
    .X(_246_)
  );
  sky130_fd_sc_hd__xnor3_1 _506_ (
    .A(_192_),
    .B(_218_),
    .C(_220_),
    .X(_247_)
  );
  sky130_fd_sc_hd__mux2_1 _507_ (
    .A0(\ra[7] ),
    .A1(a[7]),
    .S(en),
    .X(_051_)
  );
  sky130_fd_sc_hd__or2_0 _508_ (
    .A(acc[9]),
    .B(\p[9] ),
    .X(_071_)
  );
  sky130_fd_sc_hd__nand2_1 _509_ (
    .A(\ra[0] ),
    .B(\rb[5] ),
    .Y(_248_)
  );
  sky130_fd_sc_hd__nand2_1 _510_ (
    .A(\ra[1] ),
    .B(\rb[4] ),
    .Y(_249_)
  );
  sky130_fd_sc_hd__nand2_1 _511_ (
    .A(\ra[1] ),
    .B(\rb[3] ),
    .Y(_250_)
  );
  sky130_fd_sc_hd__xnor3_1 _512_ (
    .A(_225_),
    .B(_248_),
    .C(_249_),
    .X(_251_)
  );
  sky130_fd_sc_hd__maj3_1 _513_ (
    .A(_246_),
    .B(_247_),
    .C(_251_),
    .X(_252_)
  );
  sky130_fd_sc_hd__xnor3_1 _514_ (
    .A(_221_),
    .B(_222_),
    .C(_226_),
    .X(_253_)
  );
  sky130_fd_sc_hd__maj3_1 _515_ (
    .A(_225_),
    .B(_248_),
    .C(_249_),
    .X(_254_)
  );
  sky130_fd_sc_hd__nand2_1 _516_ (
    .A(\ra[0] ),
    .B(\rb[6] ),
    .Y(_255_)
  );
  sky130_fd_sc_hd__nor2_1 _517_ (
    .A(_254_),
    .B(_255_),
    .Y(_256_)
  );
  sky130_fd_sc_hd__xor2_1 _518_ (
    .A(_254_),
    .B(_255_),
    .X(_257_)
  );
  sky130_fd_sc_hd__nand2_1 _519_ (
    .A(acc[8]),
    .B(\p[8] ),
    .Y(_072_)
  );
  sky130_fd_sc_hd__xnor2_1 _520_ (
    .A(_252_),
    .B(_253_),
    .Y(_258_)
  );
  sky130_fd_sc_hd__maj3_1 _521_ (
    .A(_252_),
    .B(_253_),
    .C(_257_),
    .X(_259_)
  );
  sky130_fd_sc_hd__xor2_1 _522_ (
    .A(_232_),
    .B(_233_),
    .X(_260_)
  );
  sky130_fd_sc_hd__xor2_1 _523_ (
    .A(_259_),
    .B(_260_),
    .X(_261_)
  );
  sky130_fd_sc_hd__maj3_1 _524_ (
    .A(_256_),
    .B(_259_),
    .C(_260_),
    .X(_262_)
  );
  sky130_fd_sc_hd__xor2_1 _525_ (
    .A(_237_),
    .B(_238_),
    .X(_263_)
  );
  sky130_fd_sc_hd__nand2_1 _526_ (
    .A(_262_),
    .B(_263_),
    .Y(_264_)
  );
  sky130_fd_sc_hd__xnor2_1 _527_ (
    .A(_262_),
    .B(_263_),
    .Y(_265_)
  );
  sky130_fd_sc_hd__xnor2_1 _528_ (
    .A(_256_),
    .B(_261_),
    .Y(_266_)
  );
  sky130_fd_sc_hd__nand2_1 _529_ (
    .A(\ra[2] ),
    .B(\rb[1] ),
    .Y(_267_)
  );
  sky130_fd_sc_hd__nor2_1 _530_ (
    .A(acc[8]),
    .B(\p[8] ),
    .Y(_073_)
  );
  sky130_fd_sc_hd__nand2_1 _531_ (
    .A(\ra[2] ),
    .B(\rb[0] ),
    .Y(_268_)
  );
  sky130_fd_sc_hd__nand2_1 _532_ (
    .A(\ra[1] ),
    .B(\rb[2] ),
    .Y(_269_)
  );
  sky130_fd_sc_hd__xnor2_1 _533_ (
    .A(_244_),
    .B(_267_),
    .Y(_270_)
  );
  sky130_fd_sc_hd__maj3_1 _534_ (
    .A(_244_),
    .B(_267_),
    .C(_269_),
    .X(_271_)
  );
  sky130_fd_sc_hd__xnor3_1 _535_ (
    .A(_219_),
    .B(_243_),
    .C(_245_),
    .X(_272_)
  );
  sky130_fd_sc_hd__nand2_1 _536_ (
    .A(\ra[0] ),
    .B(\rb[4] ),
    .Y(_273_)
  );
  sky130_fd_sc_hd__nand2_1 _537_ (
    .A(\ra[0] ),
    .B(\rb[3] ),
    .Y(_274_)
  );
  sky130_fd_sc_hd__nor2_1 _538_ (
    .A(_250_),
    .B(_273_),
    .Y(_275_)
  );
  sky130_fd_sc_hd__xnor2_1 _539_ (
    .A(_250_),
    .B(_273_),
    .Y(_276_)
  );
  sky130_fd_sc_hd__maj3_1 _540_ (
    .A(_271_),
    .B(_272_),
    .C(_276_),
    .X(_277_)
  );
  sky130_fd_sc_hd__xor2_1 _541_ (
    .A(acc[8]),
    .B(\p[8] ),
    .X(_074_)
  );
  sky130_fd_sc_hd__clkinv_1 _542_ (
    .A(_277_),
    .Y(_278_)
  );
  sky130_fd_sc_hd__xor3_1 _543_ (
    .A(_246_),
    .B(_247_),
    .C(_251_),
    .X(_279_)
  );
  sky130_fd_sc_hd__xor2_1 _544_ (
    .A(_277_),
    .B(_279_),
    .X(_280_)
  );
  sky130_fd_sc_hd__maj3_1 _545_ (
    .A(_275_),
    .B(_278_),
    .C(_279_),
    .X(_281_)
  );
  sky130_fd_sc_hd__xnor2_1 _546_ (
    .A(_257_),
    .B(_258_),
    .Y(_282_)
  );
  sky130_fd_sc_hd__nand2_1 _547_ (
    .A(_281_),
    .B(_282_),
    .Y(_283_)
  );
  sky130_fd_sc_hd__xnor2_1 _548_ (
    .A(_281_),
    .B(_282_),
    .Y(_284_)
  );
  sky130_fd_sc_hd__nand2_1 _549_ (
    .A(\ra[1] ),
    .B(\rb[1] ),
    .Y(_285_)
  );
  sky130_fd_sc_hd__nand2_1 _550_ (
    .A(\ra[0] ),
    .B(\rb[2] ),
    .Y(_286_)
  );
  sky130_fd_sc_hd__xor2_1 _551_ (
    .A(_268_),
    .B(_285_),
    .X(_287_)
  );
  sky130_fd_sc_hd__and2_0 _552_ (
    .A(acc[7]),
    .B(\p[7] ),
    .X(_075_)
  );
  sky130_fd_sc_hd__maj3_1 _553_ (
    .A(_268_),
    .B(_285_),
    .C(_286_),
    .X(_288_)
  );
  sky130_fd_sc_hd__xnor2_1 _554_ (
    .A(_269_),
    .B(_270_),
    .Y(_289_)
  );
  sky130_fd_sc_hd__maj3_1 _555_ (
    .A(_274_),
    .B(_288_),
    .C(_289_),
    .X(_290_)
  );
  sky130_fd_sc_hd__xnor3_1 _556_ (
    .A(_271_),
    .B(_272_),
    .C(_276_),
    .X(_291_)
  );
  sky130_fd_sc_hd__nand2b_1 _557_ (
    .A_N(_290_),
    .B(_291_),
    .Y(_292_)
  );
  sky130_fd_sc_hd__xnor2_1 _558_ (
    .A(_275_),
    .B(_280_),
    .Y(_293_)
  );
  sky130_fd_sc_hd__nand2b_1 _559_ (
    .A_N(_292_),
    .B(_293_),
    .Y(_294_)
  );
  sky130_fd_sc_hd__nand2_1 _560_ (
    .A(\ra[0] ),
    .B(\rb[0] ),
    .Y(_295_)
  );
  sky130_fd_sc_hd__nand4_1 _561_ (
    .A(\ra[0] ),
    .B(\ra[1] ),
    .C(\rb[0] ),
    .D(\rb[1] ),
    .Y(_296_)
  );
  sky130_fd_sc_hd__xnor2_1 _562_ (
    .A(_286_),
    .B(_287_),
    .Y(_297_)
  );
  sky130_fd_sc_hd__nor2_1 _563_ (
    .A(acc[7]),
    .B(\p[7] ),
    .Y(_076_)
  );
  sky130_fd_sc_hd__nand2b_1 _564_ (
    .A_N(_296_),
    .B(_297_),
    .Y(_298_)
  );
  sky130_fd_sc_hd__xor3_1 _565_ (
    .A(_274_),
    .B(_288_),
    .C(_289_),
    .X(_299_)
  );
  sky130_fd_sc_hd__nor2_1 _566_ (
    .A(_298_),
    .B(_299_),
    .Y(_300_)
  );
  sky130_fd_sc_hd__nand2b_1 _567_ (
    .A_N(_291_),
    .B(_290_),
    .Y(_301_)
  );
  sky130_fd_sc_hd__and2_0 _568_ (
    .A(_292_),
    .B(_301_),
    .X(_302_)
  );
  sky130_fd_sc_hd__nand2_1 _569_ (
    .A(_300_),
    .B(_302_),
    .Y(_303_)
  );
  sky130_fd_sc_hd__xor2_1 _570_ (
    .A(_292_),
    .B(_293_),
    .X(_304_)
  );
  sky130_fd_sc_hd__nand4_1 _571_ (
    .A(_292_),
    .B(_293_),
    .C(_300_),
    .D(_301_),
    .Y(_305_)
  );
  sky130_fd_sc_hd__a21o_1 _572_ (
    .A1(_294_),
    .A2(_305_),
    .B1(_284_),
    .X(_306_)
  );
  sky130_fd_sc_hd__a21oi_1 _573_ (
    .A1(_283_),
    .A2(_306_),
    .B1(_266_),
    .Y(_307_)
  );
  sky130_fd_sc_hd__and2_0 _574_ (
    .A(acc[6]),
    .B(\p[6] ),
    .X(_077_)
  );
  sky130_fd_sc_hd__a211o_1 _575_ (
    .A1(_283_),
    .A2(_306_),
    .B1(_265_),
    .C1(_266_),
    .X(_308_)
  );
  sky130_fd_sc_hd__xor2_1 _576_ (
    .A(_240_),
    .B(_241_),
    .X(_309_)
  );
  sky130_fd_sc_hd__a21o_1 _577_ (
    .A1(_264_),
    .A2(_308_),
    .B1(_309_),
    .X(_310_)
  );
  sky130_fd_sc_hd__nand2_1 _578_ (
    .A(_242_),
    .B(_310_),
    .Y(_311_)
  );
  sky130_fd_sc_hd__xor2_1 _579_ (
    .A(_215_),
    .B(_216_),
    .X(_312_)
  );
  sky130_fd_sc_hd__a21boi_0 _580_ (
    .A1(_242_),
    .A2(_310_),
    .B1_N(_312_),
    .Y(_313_)
  );
  sky130_fd_sc_hd__xor2_1 _581_ (
    .A(_189_),
    .B(_190_),
    .X(_314_)
  );
  sky130_fd_sc_hd__o21a_1 _582_ (
    .A1(_217_),
    .A2(_313_),
    .B1(_314_),
    .X(_315_)
  );
  sky130_fd_sc_hd__nor3_1 _583_ (
    .A(_159_),
    .B(_162_),
    .C(_163_),
    .Y(_316_)
  );
  sky130_fd_sc_hd__nor2_1 _584_ (
    .A(_164_),
    .B(_316_),
    .Y(_317_)
  );
  sky130_fd_sc_hd__nand2_1 _585_ (
    .A(acc[1]),
    .B(\p[1] ),
    .Y(_078_)
  );
  sky130_fd_sc_hd__o21a_1 _586_ (
    .A1(_191_),
    .A2(_315_),
    .B1(_317_),
    .X(_318_)
  );
  sky130_fd_sc_hd__nand2_1 _587_ (
    .A(_137_),
    .B(_142_),
    .Y(_319_)
  );
  sky130_fd_sc_hd__nand2_1 _588_ (
    .A(_143_),
    .B(_319_),
    .Y(_320_)
  );
  sky130_fd_sc_hd__o21bai_1 _589_ (
    .A1(_164_),
    .A2(_318_),
    .B1_N(_320_),
    .Y(_321_)
  );
  sky130_fd_sc_hd__nand3_1 _590_ (
    .A(\ra[7] ),
    .B(\rb[7] ),
    .C(_127_),
    .Y(_322_)
  );
  sky130_fd_sc_hd__maj3_1 _591_ (
    .A(_133_),
    .B(_138_),
    .C(_140_),
    .X(_323_)
  );
  sky130_fd_sc_hd__xor2_1 _592_ (
    .A(_322_),
    .B(_323_),
    .X(_324_)
  );
  sky130_fd_sc_hd__a21o_1 _593_ (
    .A1(_143_),
    .A2(_321_),
    .B1(_324_),
    .X(_325_)
  );
  sky130_fd_sc_hd__o211ai_1 _594_ (
    .A1(_128_),
    .A2(_323_),
    .B1(\ra[7] ),
    .C1(\rb[7] ),
    .Y(_326_)
  );
  sky130_fd_sc_hd__a31oi_1 _595_ (
    .A1(en),
    .A2(_325_),
    .A3(_326_),
    .B1(_110_),
    .Y(_047_)
  );
  sky130_fd_sc_hd__nand2_1 _596_ (
    .A(acc[0]),
    .B(\p[0] ),
    .Y(_079_)
  );
  sky130_fd_sc_hd__mux2_1 _597_ (
    .A0(\rb[7] ),
    .A1(b[7]),
    .S(en),
    .X(_046_)
  );
  sky130_fd_sc_hd__mux2_1 _598_ (
    .A0(\ra[0] ),
    .A1(a[0]),
    .S(en),
    .X(_045_)
  );
  sky130_fd_sc_hd__mux2_1 _599_ (
    .A0(\ra[1] ),
    .A1(a[1]),
    .S(en),
    .X(_044_)
  );
  sky130_fd_sc_hd__mux2_1 _600_ (
    .A0(\ra[2] ),
    .A1(a[2]),
    .S(en),
    .X(_043_)
  );
  sky130_fd_sc_hd__mux2_1 _601_ (
    .A0(\ra[3] ),
    .A1(a[3]),
    .S(en),
    .X(_042_)
  );
  sky130_fd_sc_hd__mux2_1 _602_ (
    .A0(\ra[4] ),
    .A1(a[4]),
    .S(en),
    .X(_041_)
  );
  sky130_fd_sc_hd__mux2_1 _603_ (
    .A0(\ra[5] ),
    .A1(a[5]),
    .S(en),
    .X(_040_)
  );
  sky130_fd_sc_hd__mux2_1 _604_ (
    .A0(\ra[6] ),
    .A1(a[6]),
    .S(en),
    .X(_039_)
  );
  sky130_fd_sc_hd__xnor2_1 _605_ (
    .A(_062_),
    .B(_099_),
    .Y(_327_)
  );
  sky130_fd_sc_hd__nor2_1 _606_ (
    .A(en),
    .B(acc[12]),
    .Y(_328_)
  );
  sky130_fd_sc_hd__xnor2_1 _607_ (
    .A(acc[1]),
    .B(\p[1] ),
    .Y(_080_)
  );
  sky130_fd_sc_hd__a21oi_1 _608_ (
    .A1(en),
    .A2(_327_),
    .B1(_328_),
    .Y(_038_)
  );
  sky130_fd_sc_hd__xnor2_1 _609_ (
    .A(_069_),
    .B(_096_),
    .Y(_329_)
  );
  sky130_fd_sc_hd__nor2_1 _610_ (
    .A(en),
    .B(acc[10]),
    .Y(_330_)
  );
  sky130_fd_sc_hd__a21oi_1 _611_ (
    .A1(en),
    .A2(_329_),
    .B1(_330_),
    .Y(_037_)
  );
  sky130_fd_sc_hd__xnor2_1 _612_ (
    .A(_074_),
    .B(_094_),
    .Y(_331_)
  );
  sky130_fd_sc_hd__nor2_1 _613_ (
    .A(en),
    .B(acc[8]),
    .Y(_332_)
  );
  sky130_fd_sc_hd__a21oi_1 _614_ (
    .A1(en),
    .A2(_331_),
    .B1(_332_),
    .Y(_036_)
  );
  sky130_fd_sc_hd__xnor2_1 _615_ (
    .A(\p[15] ),
    .B(acc[15]),
    .Y(_333_)
  );
  sky130_fd_sc_hd__xnor2_1 _616_ (
    .A(_102_),
    .B(_333_),
    .Y(_334_)
  );
  sky130_fd_sc_hd__nor2_1 _617_ (
    .A(en),
    .B(acc[15]),
    .Y(_335_)
  );
  sky130_fd_sc_hd__nand2_1 _618_ (
    .A(\p[15] ),
    .B(acc[15]),
    .Y(_054_)
  );
  sky130_fd_sc_hd__o21ai_0 _619_ (
    .A1(_079_),
    .A2(_080_),
    .B1(_078_),
    .Y(_081_)
  );
  sky130_fd_sc_hd__a21oi_1 _620_ (
    .A1(en),
    .A2(_334_),
    .B1(_335_),
    .Y(_035_)
  );
  sky130_fd_sc_hd__xnor2_1 _621_ (
    .A(_089_),
    .B(_091_),
    .Y(_336_)
  );
  sky130_fd_sc_hd__nor2_1 _622_ (
    .A(en),
    .B(acc[6]),
    .Y(_337_)
  );
  sky130_fd_sc_hd__a21oi_1 _623_ (
    .A1(en),
    .A2(_336_),
    .B1(_337_),
    .Y(_034_)
  );
  sky130_fd_sc_hd__nor2_1 _624_ (
    .A(en),
    .B(acc[11]),
    .Y(_338_)
  );
  sky130_fd_sc_hd__nand2_1 _625_ (
    .A(_064_),
    .B(_066_),
    .Y(_339_)
  );
  sky130_fd_sc_hd__xnor2_1 _626_ (
    .A(_098_),
    .B(_339_),
    .Y(_340_)
  );
  sky130_fd_sc_hd__a21oi_1 _627_ (
    .A1(en),
    .A2(_340_),
    .B1(_338_),
    .Y(_033_)
  );
  sky130_fd_sc_hd__nor2b_1 _628_ (
    .A(en),
    .B_N(\p[14] ),
    .Y(_341_)
  );
  sky130_fd_sc_hd__nand3_1 _629_ (
    .A(_143_),
    .B(_321_),
    .C(_324_),
    .Y(_342_)
  );
  sky130_fd_sc_hd__xor2_1 _630_ (
    .A(acc[2]),
    .B(\p[2] ),
    .X(_082_)
  );
  sky130_fd_sc_hd__a31o_1 _631_ (
    .A1(en),
    .A2(_325_),
    .A3(_342_),
    .B1(_341_),
    .X(_032_)
  );
  sky130_fd_sc_hd__xnor2_1 _632_ (
    .A(_057_),
    .B(_101_),
    .Y(_343_)
  );
  sky130_fd_sc_hd__nor2_1 _633_ (
    .A(en),
    .B(acc[14]),
    .Y(_344_)
  );
  sky130_fd_sc_hd__a21oi_1 _634_ (
    .A1(en),
    .A2(_343_),
    .B1(_344_),
    .Y(_031_)
  );
  sky130_fd_sc_hd__nor2_1 _635_ (
    .A(acc[16]),
    .B(_104_),
    .Y(_345_)
  );
  sky130_fd_sc_hd__nor2_1 _636_ (
    .A(_105_),
    .B(_345_),
    .Y(_030_)
  );
  sky130_fd_sc_hd__xnor2_1 _637_ (
    .A(acc[13]),
    .B(\p[13] ),
    .Y(_346_)
  );
  sky130_fd_sc_hd__nand3_1 _638_ (
    .A(_060_),
    .B(_100_),
    .C(_346_),
    .Y(_347_)
  );
  sky130_fd_sc_hd__a21oi_1 _639_ (
    .A1(_060_),
    .A2(_100_),
    .B1(_346_),
    .Y(_348_)
  );
  sky130_fd_sc_hd__nor3b_1 _640_ (
    .A(_348_),
    .B(_052_),
    .C_N(_347_),
    .Y(_349_)
  );
  sky130_fd_sc_hd__maj3_1 _641_ (
    .A(acc[2]),
    .B(\p[2] ),
    .C(_081_),
    .X(_083_)
  );
  sky130_fd_sc_hd__a21o_1 _642_ (
    .A1(_052_),
    .A2(acc[13]),
    .B1(_349_),
    .X(_029_)
  );
  sky130_fd_sc_hd__xnor2_1 _643_ (
    .A(_079_),
    .B(_080_),
    .Y(_350_)
  );
  sky130_fd_sc_hd__nor2_1 _644_ (
    .A(en),
    .B(acc[1]),
    .Y(_351_)
  );
  sky130_fd_sc_hd__a21oi_1 _645_ (
    .A1(en),
    .A2(_350_),
    .B1(_351_),
    .Y(_028_)
  );
  sky130_fd_sc_hd__nor3b_1 _646_ (
    .A(_164_),
    .B(_318_),
    .C_N(_320_),
    .Y(_352_)
  );
  sky130_fd_sc_hd__nand2_1 _647_ (
    .A(en),
    .B(_321_),
    .Y(_353_)
  );
  sky130_fd_sc_hd__o2bb2ai_1 _648_ (
    .A1_N(_052_),
    .A2_N(\p[13] ),
    .B1(_352_),
    .B2(_353_),
    .Y(_027_)
  );
  sky130_fd_sc_hd__xnor2_1 _649_ (
    .A(_083_),
    .B(_084_),
    .Y(_354_)
  );
  sky130_fd_sc_hd__nor2_1 _650_ (
    .A(en),
    .B(acc[3]),
    .Y(_355_)
  );
  sky130_fd_sc_hd__a21oi_1 _651_ (
    .A1(en),
    .A2(_354_),
    .B1(_355_),
    .Y(_026_)
  );
  sky130_fd_sc_hd__xor2_1 _652_ (
    .A(acc[3]),
    .B(\p[3] ),
    .X(_084_)
  );
  sky130_fd_sc_hd__nand2_1 _653_ (
    .A(en),
    .B(\p[0] ),
    .Y(_356_)
  );
  sky130_fd_sc_hd__xnor2_1 _654_ (
    .A(acc[0]),
    .B(_356_),
    .Y(_025_)
  );
  sky130_fd_sc_hd__xnor2_1 _655_ (
    .A(_087_),
    .B(_088_),
    .Y(_357_)
  );
  sky130_fd_sc_hd__nor2_1 _656_ (
    .A(en),
    .B(acc[5]),
    .Y(_358_)
  );
  sky130_fd_sc_hd__a21oi_1 _657_ (
    .A1(en),
    .A2(_357_),
    .B1(_358_),
    .Y(_024_)
  );
  sky130_fd_sc_hd__nor3_1 _658_ (
    .A(_191_),
    .B(_315_),
    .C(_317_),
    .Y(_359_)
  );
  sky130_fd_sc_hd__nor3_1 _659_ (
    .A(_052_),
    .B(_318_),
    .C(_359_),
    .Y(_360_)
  );
  sky130_fd_sc_hd__a21o_1 _660_ (
    .A1(_052_),
    .A2(\p[12] ),
    .B1(_360_),
    .X(_023_)
  );
  sky130_fd_sc_hd__nor2_1 _661_ (
    .A(_075_),
    .B(_076_),
    .Y(_361_)
  );
  sky130_fd_sc_hd__xor2_1 _662_ (
    .A(_092_),
    .B(_361_),
    .X(_362_)
  );
  sky130_fd_sc_hd__maj3_1 _663_ (
    .A(acc[3]),
    .B(\p[3] ),
    .C(_083_),
    .X(_085_)
  );
  sky130_fd_sc_hd__mux2_1 _664_ (
    .A0(acc[7]),
    .A1(_362_),
    .S(en),
    .X(_022_)
  );
  sky130_fd_sc_hd__nor2b_1 _665_ (
    .A(_070_),
    .B_N(_071_),
    .Y(_363_)
  );
  sky130_fd_sc_hd__xnor2_1 _666_ (
    .A(_095_),
    .B(_363_),
    .Y(_364_)
  );
  sky130_fd_sc_hd__nor2_1 _667_ (
    .A(en),
    .B(acc[9]),
    .Y(_365_)
  );
  sky130_fd_sc_hd__a21oi_1 _668_ (
    .A1(en),
    .A2(_364_),
    .B1(_365_),
    .Y(_021_)
  );
  sky130_fd_sc_hd__xor2_1 _669_ (
    .A(acc[17]),
    .B(_105_),
    .X(_020_)
  );
  sky130_fd_sc_hd__xnor2_1 _670_ (
    .A(_081_),
    .B(_082_),
    .Y(_366_)
  );
  sky130_fd_sc_hd__nor2_1 _671_ (
    .A(en),
    .B(acc[2]),
    .Y(_367_)
  );
  sky130_fd_sc_hd__a21oi_1 _672_ (
    .A1(en),
    .A2(_366_),
    .B1(_367_),
    .Y(_019_)
  );
  sky130_fd_sc_hd__mux2_1 _673_ (
    .A0(\rb[0] ),
    .A1(b[0]),
    .S(en),
    .X(_018_)
  );
  sky130_fd_sc_hd__xor2_1 _674_ (
    .A(acc[4]),
    .B(\p[4] ),
    .X(_086_)
  );
  sky130_fd_sc_hd__mux2_1 _675_ (
    .A0(\rb[1] ),
    .A1(b[1]),
    .S(en),
    .X(_017_)
  );
  sky130_fd_sc_hd__mux2_1 _676_ (
    .A0(\rb[2] ),
    .A1(b[2]),
    .S(en),
    .X(_016_)
  );
  sky130_fd_sc_hd__mux2_1 _677_ (
    .A0(\rb[3] ),
    .A1(b[3]),
    .S(en),
    .X(_015_)
  );
  sky130_fd_sc_hd__mux2_1 _678_ (
    .A0(\rb[4] ),
    .A1(b[4]),
    .S(en),
    .X(_014_)
  );
  sky130_fd_sc_hd__mux2_1 _679_ (
    .A0(\rb[5] ),
    .A1(b[5]),
    .S(en),
    .X(_013_)
  );
  sky130_fd_sc_hd__mux2_1 _680_ (
    .A0(\rb[6] ),
    .A1(b[6]),
    .S(en),
    .X(_012_)
  );
  sky130_fd_sc_hd__nor2_1 _681_ (
    .A(en),
    .B(\p[0] ),
    .Y(_368_)
  );
  sky130_fd_sc_hd__a21oi_1 _682_ (
    .A1(en),
    .A2(_295_),
    .B1(_368_),
    .Y(_011_)
  );
  sky130_fd_sc_hd__a22oi_1 _683_ (
    .A1(\ra[1] ),
    .A2(\rb[0] ),
    .B1(\rb[1] ),
    .B2(\ra[0] ),
    .Y(_369_)
  );
  sky130_fd_sc_hd__nand2_1 _684_ (
    .A(en),
    .B(_296_),
    .Y(_370_)
  );
  sky130_fd_sc_hd__maj3_1 _685_ (
    .A(acc[4]),
    .B(\p[4] ),
    .C(_085_),
    .X(_087_)
  );
  sky130_fd_sc_hd__o2bb2ai_1 _686_ (
    .A1_N(_052_),
    .A2_N(\p[1] ),
    .B1(_369_),
    .B2(_370_),
    .Y(_010_)
  );
  sky130_fd_sc_hd__xor2_1 _687_ (
    .A(_296_),
    .B(_297_),
    .X(_371_)
  );
  sky130_fd_sc_hd__nor2_1 _688_ (
    .A(en),
    .B(\p[2] ),
    .Y(_372_)
  );
  sky130_fd_sc_hd__a21oi_1 _689_ (
    .A1(en),
    .A2(_371_),
    .B1(_372_),
    .Y(_009_)
  );
  sky130_fd_sc_hd__xnor2_1 _690_ (
    .A(_298_),
    .B(_299_),
    .Y(_373_)
  );
  sky130_fd_sc_hd__nor2_1 _691_ (
    .A(en),
    .B(\p[3] ),
    .Y(_374_)
  );
  sky130_fd_sc_hd__a21oi_1 _692_ (
    .A1(en),
    .A2(_373_),
    .B1(_374_),
    .Y(_008_)
  );
  sky130_fd_sc_hd__nor2_1 _693_ (
    .A(_300_),
    .B(_302_),
    .Y(_375_)
  );
  sky130_fd_sc_hd__nand2_1 _694_ (
    .A(en),
    .B(_303_),
    .Y(_376_)
  );
  sky130_fd_sc_hd__o2bb2ai_1 _695_ (
    .A1_N(_052_),
    .A2_N(\p[4] ),
    .B1(_375_),
    .B2(_376_),
    .Y(_007_)
  );
  sky130_fd_sc_hd__xor2_1 _696_ (
    .A(acc[5]),
    .B(\p[5] ),
    .X(_088_)
  );
  sky130_fd_sc_hd__nand2_1 _697_ (
    .A(_303_),
    .B(_304_),
    .Y(_377_)
  );
  sky130_fd_sc_hd__nand2_1 _698_ (
    .A(_305_),
    .B(_377_),
    .Y(_378_)
  );
  sky130_fd_sc_hd__nor2_1 _699_ (
    .A(en),
    .B(\p[5] ),
    .Y(_379_)
  );
  sky130_fd_sc_hd__a21oi_1 _700_ (
    .A1(en),
    .A2(_378_),
    .B1(_379_),
    .Y(_006_)
  );
  sky130_fd_sc_hd__nand3_1 _701_ (
    .A(_284_),
    .B(_294_),
    .C(_305_),
    .Y(_380_)
  );
  sky130_fd_sc_hd__a21oi_1 _702_ (
    .A1(_306_),
    .A2(_380_),
    .B1(_052_),
    .Y(_381_)
  );
  sky130_fd_sc_hd__nor2_1 _703_ (
    .A(en),
    .B(\p[6] ),
    .Y(_382_)
  );
  sky130_fd_sc_hd__nor2_1 _704_ (
    .A(_381_),
    .B(_382_),
    .Y(_005_)
  );
  sky130_fd_sc_hd__nor2_1 _705_ (
    .A(en),
    .B(\p[7] ),
    .Y(_383_)
  );
  sky130_fd_sc_hd__nand3_1 _706_ (
    .A(_266_),
    .B(_283_),
    .C(_306_),
    .Y(_384_)
  );
  sky130_fd_sc_hd__maj3_1 _707_ (
    .A(acc[5]),
    .B(\p[5] ),
    .C(_087_),
    .X(_089_)
  );
  sky130_fd_sc_hd__nand2b_1 _708_ (
    .A_N(_307_),
    .B(_384_),
    .Y(_385_)
  );
  sky130_fd_sc_hd__a21oi_1 _709_ (
    .A1(en),
    .A2(_385_),
    .B1(_383_),
    .Y(_004_)
  );
  sky130_fd_sc_hd__xor2_1 _710_ (
    .A(_265_),
    .B(_307_),
    .X(_386_)
  );
  sky130_fd_sc_hd__nor2_1 _711_ (
    .A(en),
    .B(\p[8] ),
    .Y(_387_)
  );
  sky130_fd_sc_hd__a21oi_1 _712_ (
    .A1(en),
    .A2(_386_),
    .B1(_387_),
    .Y(_003_)
  );
  sky130_fd_sc_hd__nand3_1 _713_ (
    .A(_264_),
    .B(_308_),
    .C(_309_),
    .Y(_388_)
  );
  sky130_fd_sc_hd__a21oi_1 _714_ (
    .A1(_310_),
    .A2(_388_),
    .B1(_052_),
    .Y(_389_)
  );
  sky130_fd_sc_hd__nor2_1 _715_ (
    .A(en),
    .B(\p[9] ),
    .Y(_390_)
  );
  sky130_fd_sc_hd__nor2_1 _716_ (
    .A(_389_),
    .B(_390_),
    .Y(_002_)
  );
  sky130_fd_sc_hd__xnor2_1 _717_ (
    .A(_311_),
    .B(_312_),
    .Y(_391_)
  );
  sky130_fd_sc_hd__nor2_1 _718_ (
    .A(acc[6]),
    .B(\p[6] ),
    .Y(_090_)
  );
  sky130_fd_sc_hd__nor2_1 _719_ (
    .A(en),
    .B(\p[10] ),
    .Y(_392_)
  );
  sky130_fd_sc_hd__a21oi_1 _720_ (
    .A1(en),
    .A2(_391_),
    .B1(_392_),
    .Y(_001_)
  );
  sky130_fd_sc_hd__nor3_1 _721_ (
    .A(_217_),
    .B(_313_),
    .C(_314_),
    .Y(_393_)
  );
  sky130_fd_sc_hd__nor3_1 _722_ (
    .A(_052_),
    .B(_315_),
    .C(_393_),
    .Y(_394_)
  );
  sky130_fd_sc_hd__a21o_1 _723_ (
    .A1(_052_),
    .A2(\p[11] ),
    .B1(_394_),
    .X(_000_)
  );
  sky130_fd_sc_hd__and2_0 _724_ (
    .A(\p[14] ),
    .B(acc[14]),
    .X(_055_)
  );
  sky130_fd_sc_hd__nor2_1 _725_ (
    .A(_077_),
    .B(_090_),
    .Y(_091_)
  );
  sky130_fd_sc_hd__a21o_1 _726_ (
    .A1(_089_),
    .A2(_091_),
    .B1(_077_),
    .X(_092_)
  );
  sky130_fd_sc_hd__a211oi_1 _727_ (
    .A1(_089_),
    .A2(_091_),
    .B1(_075_),
    .C1(_077_),
    .Y(_093_)
  );
  sky130_fd_sc_hd__nor2_1 _728_ (
    .A(_076_),
    .B(_093_),
    .Y(_094_)
  );
  sky130_fd_sc_hd__o31ai_1 _729_ (
    .A1(_073_),
    .A2(_076_),
    .A3(_093_),
    .B1(_072_),
    .Y(_095_)
  );
  sky130_fd_sc_hd__o21a_1 _730_ (
    .A1(_070_),
    .A2(_095_),
    .B1(_071_),
    .X(_096_)
  );
  sky130_fd_sc_hd__o211a_1 _731_ (
    .A1(_070_),
    .A2(_095_),
    .B1(_071_),
    .C1(_069_),
    .X(_097_)
  );
  sky130_fd_sc_hd__nor2_1 _732_ (
    .A(_067_),
    .B(_097_),
    .Y(_098_)
  );
  sky130_fd_sc_hd__a21oi_1 _733_ (
    .A1(_064_),
    .A2(_098_),
    .B1(_065_),
    .Y(_099_)
  );
  sky130_fd_sc_hd__o311ai_0 _734_ (
    .A1(_063_),
    .A2(_067_),
    .A3(_097_),
    .B1(_066_),
    .C1(_062_),
    .Y(_100_)
  );
  sky130_fd_sc_hd__nor2_1 _735_ (
    .A(\p[14] ),
    .B(acc[14]),
    .Y(_056_)
  );
  sky130_fd_sc_hd__a31oi_1 _736_ (
    .A1(_058_),
    .A2(_060_),
    .A3(_100_),
    .B1(_059_),
    .Y(_101_)
  );
  sky130_fd_sc_hd__a21oi_1 _737_ (
    .A1(_057_),
    .A2(_101_),
    .B1(_055_),
    .Y(_102_)
  );
  sky130_fd_sc_hd__o21ai_0 _738_ (
    .A1(\p[15] ),
    .A2(acc[15]),
    .B1(en),
    .Y(_103_)
  );
  sky130_fd_sc_hd__a21oi_1 _739_ (
    .A1(_054_),
    .A2(_102_),
    .B1(_103_),
    .Y(_104_)
  );
  sky130_fd_sc_hd__a211oi_1 _740_ (
    .A1(_054_),
    .A2(_102_),
    .B1(_103_),
    .C1(_053_),
    .Y(_105_)
  );
  sky130_fd_sc_hd__nand2_1 _741_ (
    .A(acc[17]),
    .B(_105_),
    .Y(_106_)
  );
  sky130_fd_sc_hd__nand3_1 _742_ (
    .A(acc[18]),
    .B(acc[17]),
    .C(_105_),
    .Y(_107_)
  );
  sky130_fd_sc_hd__xnor2_1 _743_ (
    .A(acc[18]),
    .B(_106_),
    .Y(_050_)
  );
  sky130_fd_sc_hd__xnor2_1 _744_ (
    .A(_085_),
    .B(_086_),
    .Y(_108_)
  );
  sky130_fd_sc_hd__nor2_1 _745_ (
    .A(en),
    .B(acc[4]),
    .Y(_109_)
  );
  sky130_fd_sc_hd__nor2_1 _746_ (
    .A(_055_),
    .B(_056_),
    .Y(_057_)
  );
  sky130_fd_sc_hd__a21oi_1 _747_ (
    .A1(en),
    .A2(_108_),
    .B1(_109_),
    .Y(_049_)
  );
  sky130_fd_sc_hd__xnor2_1 _748_ (
    .A(acc[19]),
    .B(_107_),
    .Y(_048_)
  );
  sky130_fd_sc_hd__nor2_1 _749_ (
    .A(en),
    .B(\p[15] ),
    .Y(_110_)
  );
  sky130_fd_sc_hd__nand2_1 _750_ (
    .A(\rb[7] ),
    .B(\ra[4] ),
    .Y(_111_)
  );
  sky130_fd_sc_hd__nand2_1 _751_ (
    .A(\ra[6] ),
    .B(\rb[3] ),
    .Y(_112_)
  );
  sky130_fd_sc_hd__nand2_1 _752_ (
    .A(\ra[6] ),
    .B(\rb[4] ),
    .Y(_113_)
  );
  sky130_fd_sc_hd__nand2_1 _753_ (
    .A(\ra[7] ),
    .B(\rb[3] ),
    .Y(_114_)
  );
  sky130_fd_sc_hd__nand2_1 _754_ (
    .A(\ra[5] ),
    .B(\rb[5] ),
    .Y(_115_)
  );
  sky130_fd_sc_hd__xnor2_1 _755_ (
    .A(_113_),
    .B(_114_),
    .Y(_116_)
  );
  sky130_fd_sc_hd__maj3_1 _756_ (
    .A(_113_),
    .B(_114_),
    .C(_115_),
    .X(_117_)
  );
  sky130_fd_sc_hd__nand2_1 _757_ (
    .A(acc[13]),
    .B(\p[13] ),
    .Y(_058_)
  );
  sky130_fd_sc_hd__nand2_1 _758_ (
    .A(\ra[5] ),
    .B(\rb[6] ),
    .Y(_118_)
  );
  sky130_fd_sc_hd__xnor2_1 _759_ (
    .A(_117_),
    .B(_118_),
    .Y(_119_)
  );
  sky130_fd_sc_hd__xnor2_1 _760_ (
    .A(_111_),
    .B(_119_),
    .Y(_120_)
  );
  sky130_fd_sc_hd__nand2_1 _761_ (
    .A(\ra[7] ),
    .B(\rb[5] ),
    .Y(_121_)
  );
  sky130_fd_sc_hd__nor2_1 _762_ (
    .A(_113_),
    .B(_121_),
    .Y(_122_)
  );
  sky130_fd_sc_hd__a22oi_1 _763_ (
    .A1(\ra[7] ),
    .A2(\rb[4] ),
    .B1(\rb[5] ),
    .B2(\ra[6] ),
    .Y(_123_)
  );
  sky130_fd_sc_hd__nor2_1 _764_ (
    .A(_122_),
    .B(_123_),
    .Y(_124_)
  );
  sky130_fd_sc_hd__nand2b_1 _765_ (
    .A_N(_120_),
    .B(_124_),
    .Y(_125_)
  );
  sky130_fd_sc_hd__nand2_1 _766_ (
    .A(\rb[7] ),
    .B(\ra[5] ),
    .Y(_126_)
  );
  sky130_fd_sc_hd__nand2_1 _767_ (
    .A(\ra[6] ),
    .B(\rb[6] ),
    .Y(_127_)
  );
  sky130_fd_sc_hd__nor2_1 _768_ (
    .A(acc[13]),
    .B(\p[13] ),
    .Y(_059_)
  );
  sky130_fd_sc_hd__clkinv_1 _769_ (
    .A(_127_),
    .Y(_128_)
  );
  sky130_fd_sc_hd__nor2_1 _770_ (
    .A(_122_),
    .B(_128_),
    .Y(_129_)
  );
  sky130_fd_sc_hd__nand2_1 _771_ (
    .A(\rb[6] ),
    .B(_122_),
    .Y(_130_)
  );
  sky130_fd_sc_hd__a21oi_1 _772_ (
    .A1(\rb[6] ),
    .A2(_122_),
    .B1(_129_),
    .Y(_131_)
  );
  sky130_fd_sc_hd__xnor2_1 _773_ (
    .A(_126_),
    .B(_131_),
    .Y(_132_)
  );
  sky130_fd_sc_hd__nor2b_1 _774_ (
    .A(_121_),
    .B_N(_132_),
    .Y(_133_)
  );
  sky130_fd_sc_hd__xor2_1 _775_ (
    .A(_121_),
    .B(_132_),
    .X(_134_)
  );
  sky130_fd_sc_hd__maj3_1 _776_ (
    .A(_111_),
    .B(_117_),
    .C(_118_),
    .X(_135_)
  );
  sky130_fd_sc_hd__xnor2_1 _777_ (
    .A(_125_),
    .B(_134_),
    .Y(_136_)
  );
  sky130_fd_sc_hd__maj3_1 _778_ (
    .A(_125_),
    .B(_134_),
    .C(_135_),
    .X(_137_)
  );
  sky130_fd_sc_hd__nand2_1 _779_ (
    .A(acc[12]),
    .B(\p[12] ),
    .Y(_060_)
  );
  sky130_fd_sc_hd__o21ai_0 _780_ (
    .A1(_126_),
    .A2(_129_),
    .B1(_130_),
    .Y(_138_)
  );
  sky130_fd_sc_hd__a22oi_1 _781_ (
    .A1(\rb[7] ),
    .A2(\ra[6] ),
    .B1(\rb[6] ),
    .B2(\ra[7] ),
    .Y(_139_)
  );
  sky130_fd_sc_hd__a31oi_1 _782_ (
    .A1(\ra[7] ),
    .A2(\rb[7] ),
    .A3(_128_),
    .B1(_139_),
    .Y(_140_)
  );
  sky130_fd_sc_hd__xnor2_1 _783_ (
    .A(_133_),
    .B(_140_),
    .Y(_141_)
  );
  sky130_fd_sc_hd__xor2_1 _784_ (
    .A(_138_),
    .B(_141_),
    .X(_142_)
  );
  sky130_fd_sc_hd__or2_0 _785_ (
    .A(_137_),
    .B(_142_),
    .X(_143_)
  );
  sky130_fd_sc_hd__nand2_1 _786_ (
    .A(\ra[6] ),
    .B(\rb[1] ),
    .Y(_144_)
  );
  sky130_fd_sc_hd__nand2_1 _787_ (
    .A(\ra[4] ),
    .B(\rb[5] ),
    .Y(_145_)
  );
  sky130_fd_sc_hd__nand2_1 _788_ (
    .A(\ra[5] ),
    .B(\rb[4] ),
    .Y(_146_)
  );
  sky130_fd_sc_hd__nand2_1 _789_ (
    .A(\ra[5] ),
    .B(\rb[3] ),
    .Y(_147_)
  );
  sky130_fd_sc_hd__dfrtp_1 _790_ (
    .CLK(clk),
    .D(_012_),
    .Q(\rb[6] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _791_ (
    .CLK(clk),
    .D(_046_),
    .Q(\rb[7] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _792_ (
    .CLK(clk),
    .D(_011_),
    .Q(\p[0] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _793_ (
    .CLK(clk),
    .D(_010_),
    .Q(\p[1] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _794_ (
    .CLK(clk),
    .D(_009_),
    .Q(\p[2] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _795_ (
    .CLK(clk),
    .D(_008_),
    .Q(\p[3] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _796_ (
    .CLK(clk),
    .D(_007_),
    .Q(\p[4] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _797_ (
    .CLK(clk),
    .D(_006_),
    .Q(\p[5] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _798_ (
    .CLK(clk),
    .D(_005_),
    .Q(\p[6] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _799_ (
    .CLK(clk),
    .D(_004_),
    .Q(\p[7] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _800_ (
    .CLK(clk),
    .D(_003_),
    .Q(\p[8] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _801_ (
    .CLK(clk),
    .D(_002_),
    .Q(\p[9] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _802_ (
    .CLK(clk),
    .D(_001_),
    .Q(\p[10] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _803_ (
    .CLK(clk),
    .D(_000_),
    .Q(\p[11] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _804_ (
    .CLK(clk),
    .D(_023_),
    .Q(\p[12] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _805_ (
    .CLK(clk),
    .D(_027_),
    .Q(\p[13] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _806_ (
    .CLK(clk),
    .D(_032_),
    .Q(\p[14] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _807_ (
    .CLK(clk),
    .D(_047_),
    .Q(\p[15] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _808_ (
    .CLK(clk),
    .D(_025_),
    .Q(acc[0]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _809_ (
    .CLK(clk),
    .D(_028_),
    .Q(acc[1]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _810_ (
    .CLK(clk),
    .D(_019_),
    .Q(acc[2]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _811_ (
    .CLK(clk),
    .D(_026_),
    .Q(acc[3]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _812_ (
    .CLK(clk),
    .D(_049_),
    .Q(acc[4]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _813_ (
    .CLK(clk),
    .D(_024_),
    .Q(acc[5]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _814_ (
    .CLK(clk),
    .D(_034_),
    .Q(acc[6]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _815_ (
    .CLK(clk),
    .D(_022_),
    .Q(acc[7]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _816_ (
    .CLK(clk),
    .D(_036_),
    .Q(acc[8]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _817_ (
    .CLK(clk),
    .D(_021_),
    .Q(acc[9]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _818_ (
    .CLK(clk),
    .D(_037_),
    .Q(acc[10]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _819_ (
    .CLK(clk),
    .D(_033_),
    .Q(acc[11]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _820_ (
    .CLK(clk),
    .D(_038_),
    .Q(acc[12]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _821_ (
    .CLK(clk),
    .D(_029_),
    .Q(acc[13]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _822_ (
    .CLK(clk),
    .D(_031_),
    .Q(acc[14]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _823_ (
    .CLK(clk),
    .D(_035_),
    .Q(acc[15]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _824_ (
    .CLK(clk),
    .D(_030_),
    .Q(acc[16]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _825_ (
    .CLK(clk),
    .D(_020_),
    .Q(acc[17]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _826_ (
    .CLK(clk),
    .D(_050_),
    .Q(acc[18]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _827_ (
    .CLK(clk),
    .D(_048_),
    .Q(acc[19]),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _828_ (
    .CLK(clk),
    .D(_045_),
    .Q(\ra[0] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _829_ (
    .CLK(clk),
    .D(_044_),
    .Q(\ra[1] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _830_ (
    .CLK(clk),
    .D(_043_),
    .Q(\ra[2] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _831_ (
    .CLK(clk),
    .D(_042_),
    .Q(\ra[3] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _832_ (
    .CLK(clk),
    .D(_041_),
    .Q(\ra[4] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _833_ (
    .CLK(clk),
    .D(_040_),
    .Q(\ra[5] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _834_ (
    .CLK(clk),
    .D(_039_),
    .Q(\ra[6] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _835_ (
    .CLK(clk),
    .D(_051_),
    .Q(\ra[7] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _836_ (
    .CLK(clk),
    .D(_018_),
    .Q(\rb[0] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _837_ (
    .CLK(clk),
    .D(_017_),
    .Q(\rb[1] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _838_ (
    .CLK(clk),
    .D(_016_),
    .Q(\rb[2] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _839_ (
    .CLK(clk),
    .D(_015_),
    .Q(\rb[3] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _840_ (
    .CLK(clk),
    .D(_014_),
    .Q(\rb[4] ),
    .RESET_B(rst_n)
  );
  sky130_fd_sc_hd__dfrtp_1 _841_ (
    .CLK(clk),
    .D(_013_),
    .Q(\rb[5] ),
    .RESET_B(rst_n)
  );
endmodule


    
Check yourself

      

        
Predict the outputThe MAC at 40 % utilization reports 42.35 % after detailed placement. You raise the placer's target density from 0.6 to 0.9, so the cells and the pins near them crowd closer together. What utilization does detailed placement report now, in %?
      
create_clock -name clk -period 10 [get_ports clk]
set_input_delay 2 -clock clk [delete_from_list [all_inputs] [get_ports clk]]
set_output_delay 2 -clock clk [all_outputs]


      

      

      


ConceptA pin is on met3, a horizontal layer here. Which edges does this flow assign it to?


ConceptWhy does the flow run global placement twice around place_pins?


ConceptWhich place_pins call breaks this platform's layer rule?


ConceptWhy are a block's pin edges agreed with the top level before the block is placed?

        

        
      

    

    
Remember
  • Pins on the left and right edges use a horizontal layer (met3 here), pins on the top and bottom a vertical one (met2).
  • The flow places cells without the I/O, places each pin near its cells, then places the cells again with the pins fixed.
  • The placer pulls cells toward their pins, so a poor pin plan lengthens internal wires, not only the I/O nets.
  • Pin edges are an agreement with the top level; set_io_pin_constraint holds a bus to an edge or a region.