Repairing design rules: slew, capacitance, fanout

Find the nets that break the library's slew, capacitance and fanout limits, fix them with buffers and stronger drivers, and see why this comes before any timing repair.

Lesson: L4.4
Time: 30 min
Runs on: OpenROAD
Check: 5 questions

The MAC's active-low reset drives the RESET_B pins of all 52 flops from one input port, and a buf_1 drives that port. The release edge reached the flops with a slew of 2.1688 ns, beyond the pins' 1.5 ns limit and past the last slew the flops' tables list.

Timing pathThe reset release before repairRecovery check from the rst_n port to one flop's RESET_B, the port driven by a buf_1.

rst_n → _790_recovery check, latest arrival0 cells

Clock latency
Cell delay
Recovery time

A slow release
The buf_1 driving the port needs 1.4789 ns to move 188.864 fF of RESET_B pins.
The slew
The edge arrives with a 2.1688 ns slew. Every flop's recovery check reads its tables far outside their range.
Slack met with extrapolated recovery
The recovery slack is 2.7670 ns, but it rests on extrapolated tables.

Read the path as a table

Launch: clk rise edge at 0.0000 ns, clock latency 0.0000 ns (ideal). Capture: clk rise edge at 4.6000 ns, latency 0.0000 ns, library recovery time −0.3541 ns.

Arrival 1.4789 ns, required 4.2459 ns, slack 2.7670 ns (met).

Cell	Arc	Through	Edge	Delay (ns)	Time (ns)	Slew (ns)
	`rst_n` → `_790_/RESET_B`	wire rst_n	rise	0.0000	1.4789	2.1688

The report

Startpoint: rst_n (input port clocked by clk)
Endpoint: _790_ (recovery check against rising-edge clock clk)
Path Group: asynchronous
Path Type: max

Fanout       Cap      Slew     Delay      Time   Description
-------------------------------------------------------------------------------------
                    0.0000    0.0000    0.0000   clock clk (rise edge)
                              0.0000    0.0000   clock network delay (ideal)
                              0.0000    0.0000 ^ input external delay
    52    0.1889    2.1688    1.4789    1.4789 ^ rst_n (in)
                                                 rst_n (net)
                    2.1688    0.0000    1.4789 ^ _790_/RESET_B (sky130_fd_sc_hd__dfrtp_1)
                                        1.4789   data arrival time

                    0.0000    4.6000    4.6000   clock clk (rise edge)
                              0.0000    4.6000   clock network delay (ideal)
                              0.0000    4.6000   clock reconvergence pessimism
                                        4.6000 ^ _790_/CLK (sky130_fd_sc_hd__dfrtp_1)
                             -0.3541    4.2459   library recovery time
                                        4.2459   data required time
-------------------------------------------------------------------------------------
                                        4.2459   data required time
                                       -1.4789   data arrival time
-------------------------------------------------------------------------------------
                                        2.7670   slack (MET)

OpenSTA 3.1.0 on the sky130 tt library, the MAC netlist before placement, no wires.

The timing report said the reset met its checks. The library said the numbers behind that answer were outside anything it had measured.

Three electrical limits

Every net must satisfy the library's electrical limits, its design rules, for implementation closure. A net that breaks one is a design rule violation (DRV).

Rule	What it limits	Here
Max transition	The slew at every pin	1.5 ns on the RESET_B pin (the library default); `set_max_transition` can tighten it
Max capacitance	The load on every output	`buf_1` 0.1300 pF, `buf_4` 0.5612 pF, `inv_1` 0.1813 pF
Max fanout	The number of loads on a net	No limit in this library; `set_max_fanout` sets one

Limits from the pinned sky130_fd_sc_hd tt Liberty (max_transition, max_capacitance) and the SDC.

The reset's load is 52 × 3.632 fF = 0.1889 pF before any wire. The buf_1 may drive 0.1300 pF. Electrical limits and table index bounds are separate checks. This reset also exceeds its recovery table's slew axis, requiring extrapolation (L2.2). Slow edges also burn power while they cross the switching threshold and pick up noise from neighbours.

In this MAC the same kind of buf_1 drives the enable port too. After global placement, with wires estimated, 123 pins are over the slew limit and 2 outputs over the capacitance limit, all on those two nets.

Buffering and resizing

repair_design fixes design rules with two moves. Resizing swaps a driver for a stronger cell of the same function. Buffering splits a net's loads into groups and drives each group from a new buffer, a buffer tree for a large fanout. A port's driver is outside the block, so the reset net can only be buffered.

One large net split into a buffer treeArrows are signal flow. Each buffer drives a share of the loads, so no output sees the whole load.

The port sees two pins
The weak driver now loads only two buffer inputs and the wire to them.
Each buffer sees its group
Each buffer sits near its flops, so its wire is short and its load is within its limit.

Read the diagram as text

rst_n port: Driven by a weak cell
Buffer: Near the first group
Buffer: Near the second group
Flops, group 1: RESET_B pins
Flops, group 2: RESET_B pins

rst_n port → Buffer
rst_n port → Buffer
Buffer → Flops, group 1
Buffer → Flops, group 2

The shape only; repair_design chooses the number of buffers, their cells and their places.

repair_design needs placement. It estimates each net's wire capacitance from the pin positions and puts its buffers near the loads they drive. On the MAC it added 5 buf_8 and 1 buf_16, 6 buffers in all, resized 0 cells and grew the cell area by 102.5984 µm².

It works net by net. For each violating net it estimates the wire from a Steiner tree of the placed pins, then searches for a buffering or sizing repair. The heuristic is not guaranteed to find the smallest fix or clear every violation. A load far from the driver gets a buffer near it; a cluster of loads gets a buffer of its own. Long wires get buffers along their length even when no limit is broken yet, because a long wire's slew grows quickly.

LayoutThe MAC before and after repair_designGlobal placement, then repair_design and legalization. The added buffers are drawn as buffers.

Tap cells
Logic
Buffers and inverters
Flip-flops
I/O pins

Stage: Detailed placement
Cell area: 4,435.5 µm²
Utilization: 43.4 %
Wirelength (HPWL): 6,566 µm
Worst max slack: −0.2649 ns
Total negative max slack: −1.0038 ns
Worst min slack: 0.0226 ns

Before repair
After global placement, with wires estimated: 123 slew and 2 capacitance violations.
After repair
6 buffers in the reset and enable nets, legalized: 0 slew, 0 capacitance and 0 fanout violations.

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.

Stage	Cell area	Utilization	Wirelength (HPWL)	Worst max slack	Total negative max slack	Worst min slack	Overflow	Cells placed
Floorplan	4,332.9 µm²	42.4 %	—	0.3041 ns	0.0000 ns	0.1642 ns	—	136 tap cells; I/O pins not placed yet
Global placement	4,332.9 µm²	42.4 %	4,952 µm	−0.1371 ns	−0.4994 ns	0.1905 ns	0.0994	136 tap cells, 6 buffers and inverters, 389 logic, 52 flip-flops
Detailed placement	4,435.5 µm²	43.4 %	6,566 µm	−0.2649 ns	−1.0038 ns	0.0226 ns	—	136 tap cells, 12 buffers and inverters, 389 logic, 52 flip-flops

OpenROAD 26Q2 on sky130hd: global_placement, estimate_parasitics -placement, repair_design, detailed_placement.

The reset after repair

After the repair, the release reaches a flop through a buf_8 that drives 0.0625 pF. Its slew at RESET_B is 0.1441 ns, and it arrives at 0.9732 ns against 1.4789 ns before.

Timing pathThe reset release after repairThe worst recovery path of the repaired, legal placement, with wires estimated.

rst_n → _809_recovery check, latest arrival2 cells

Clock latency
Cell delay
Wire delay
Recovery time

Through the new buffer
The port drives the buffer inputs; one buffer drives the flops near it.
Recovery
Slack 3.8175 ns, with RESET_B slew back within the recovery table axis.

Read the path as a table

Launch: clk rise edge at 0.0000 ns, clock latency 0.0000 ns (ideal). Capture: clk rise edge at 4.6000 ns, latency 0.0000 ns, library recovery time 0.1907 ns.

Arrival 0.9732 ns, required 4.7907 ns, slack 3.8175 ns (met).

Cell	Arc	Through	Edge	Delay (ns)	Time (ns)	Slew (ns)
	`rst_n` → `load_slew3/A`	wire rst_n	rise	0.0000	0.5295	0.7737
1	`load_slew3/A` → `load_slew3/X`	buf_8	rise	0.2436	0.7731	0.1134
	`load_slew3/X` → `load_slew2/A`	wire net3	rise	0.0026	0.7757	0.1134
2	`load_slew2/A` → `load_slew2/X`	buf_8	rise	0.1889	0.9646	0.1433
	`load_slew2/X` → `_809_/RESET_B`	wire net2	rise	0.0086	0.9732	0.1441

The report

Startpoint: rst_n (input port clocked by clk)
Endpoint: _809_ (recovery check against rising-edge clock clk)
Path Group: asynchronous
Path Type: max

Fanout       Cap      Slew     Delay      Time   Description
-------------------------------------------------------------------------------------
                    0.0000    0.0000    0.0000   clock clk (rise edge)
                              0.0000    0.0000   clock network delay (ideal)
                              0.0000    0.0000 ^ input external delay
    11    0.0673    0.7737    0.5295    0.5295 ^ rst_n (in)
                                                 rst_n (net)
                    0.7737    0.0000    0.5295 ^ load_slew3/A (sky130_fd_sc_hd__buf_8)
    11    0.0625    0.1134    0.2436    0.7731 ^ load_slew3/X (sky130_fd_sc_hd__buf_8)
                                                 net3 (net)
                    0.1134    0.0026    0.7757 ^ load_slew2/A (sky130_fd_sc_hd__buf_8)
    16    0.0856    0.1433    0.1889    0.9646 ^ load_slew2/X (sky130_fd_sc_hd__buf_8)
                                                 net2 (net)
                    0.1441    0.0086    0.9732 ^ _809_/RESET_B (sky130_fd_sc_hd__dfrtp_1)
                                        0.9732   data arrival time

                    0.0000    4.6000    4.6000   clock clk (rise edge)
                              0.0000    4.6000   clock network delay (ideal)
                              0.0000    4.6000   clock reconvergence pessimism
                                        4.6000 ^ _809_/CLK (sky130_fd_sc_hd__dfrtp_1)
                              0.1907    4.7907   library recovery time
                                        4.7907   data required time
-------------------------------------------------------------------------------------
                                        4.7907   data required time
                                       -0.9732   data arrival time
-------------------------------------------------------------------------------------
                                        3.8175   slack (MET)

OpenROAD 26Q2 flow, after detailed placement, parasitics estimated from placement.

A faster release has a cost. The removal check (L2.1) asks that reset is released late enough after a clock edge. The release now arrives sooner, so the worst removal slack is down to 0.0226 ns.

The removal path after repair

Timing pathRemoval check after repair

rst_n → _827_removal check, earliest arrival0 cells

Clock latency
Cell delay
Removal time

Read the path as a table

Launch: clk rise edge at 0.0000 ns, clock latency 0.0000 ns (ideal). Capture: clk rise edge at 0.0000 ns, latency 0.0000 ns, library removal time 0.5064 ns.

Arrival 0.5290 ns, required 0.5064 ns, slack 0.0226 ns (met).

Cell	Arc	Through	Edge	Delay (ns)	Time (ns)	Slew (ns)
	`rst_n` → `_827_/RESET_B`	wire rst_n	rise	0.0000	0.5290	0.7737

The report

Startpoint: rst_n (input port clocked by clk)
Endpoint: _827_ (removal check against rising-edge clock clk)
Path Group: asynchronous
Path Type: min

Fanout       Cap      Slew     Delay      Time   Description
-------------------------------------------------------------------------------------
                    0.0000    0.0000    0.0000   clock clk (rise edge)
                              0.0000    0.0000   clock network delay (ideal)
                              0.0000    0.0000 ^ input external delay
    11    0.0673    0.7737    0.5290    0.5290 ^ rst_n (in)
                                                 rst_n (net)
                    0.7737    0.0000    0.5290 ^ _827_/RESET_B (sky130_fd_sc_hd__dfrtp_1)
                                        0.5290   data arrival time

                    0.0000    0.0000    0.0000   clock clk (rise edge)
                              0.0000    0.0000   clock network delay (ideal)
                              0.0000    0.0000   clock reconvergence pessimism
                                        0.0000 ^ _827_/CLK (sky130_fd_sc_hd__dfrtp_1)
                              0.5064    0.5064   library removal time
                                        0.5064   data required time
-------------------------------------------------------------------------------------
                                        0.5064   data required time
                                       -0.5290   data arrival time
-------------------------------------------------------------------------------------
                                        0.0226   slack (MET)

The same flow, worst min path.

Reset and enable nets are the high-fanout nets of most blocks, after the clock. The clock gets its own balanced tree in clock tree synthesis (L5), because its skew matters. Reset gets a buffer tree here; its release is then timed by the recovery and removal checks, as R2.2 warned.

Repair electrical violations before final timing optimization, then check both again. Table coverage is separate: a legal load may still lie outside a characterized table.

Asked in interviews

What are design rule violations in physical design?
Nets that break the library's electrical limits: max transition (slew), max capacitance (load) and max fanout, plus long-wire limits. They are fixed before timing.
How do you fix a high-fanout net?
Build a buffer tree: split the loads into groups near each other and drive each group from a buffer, or resize the driver if one cell can carry the load.
Why fix max transition and capacitance before setup?
Electrical limits constrain acceptable operation; table coverage separately determines whether delay lookup interpolates or extrapolates. Slow slews also cost power and invite noise.
How is a reset net handled differently from a clock?
The clock gets a balanced tree in CTS because skew matters. Reset gets an ordinary buffer tree from design-rule repair, and its release is timed by recovery and removal checks.

Try it

The flow places the MAC, runs repair_design and legalizes. Output lists the violations after global placement (123 slew, 2 capacitance) and after the repair, with the buffers it added (6).

Now add set_max_fanout 16 [current_design] to the SDC and run again. The fanout check now flags the reset and enable nets too, and the repair builds deeper trees: count the buffers. Then try set_max_transition 0.5 [current_design].

FLOWOpenROAD 26Q2 · sky130hd · simulator service

Edit the constraints, then run them

Expected: global placement drvSlew 123 detailed placement rdAdded 6 detailed placement drvSlew 0

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_;
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  wire _059_;
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  wire _061_;
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  wire _071_;
  wire _072_;
  wire _073_;
  wire _074_;
  wire _075_;
  wire _076_;
  wire _077_;
  wire _078_;
  wire _079_;
  wire _080_;
  wire _081_;
  wire _082_;
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  wire _084_;
  wire _085_;
  wire _086_;
  wire _087_;
  wire _088_;
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  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_;
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  wire _135_;
  wire _136_;
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  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 outputA buf_1 drives the RESET_B pins of 52 dfrtp_1 flops, and nothing else. The pin's rise capacitance is 3.632 fF. What load, in pF, does the report print on the buffer's output for the rising release?

create_clock -name clk -period 4.6 [get_ports clk]
set_input_delay 0 -clock clk [get_ports rst_n]

Read the netlist: design.v

module rst_tree (clk, rst_n, d, q);
  input clk;
  input rst_n;
  input d;
  output [51:0] q;
  wire r;
  sky130_fd_sc_hd__buf_1 b0 (.A(rst_n), .X(r));
  sky130_fd_sc_hd__dfrtp_1 f0 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[0]));
  sky130_fd_sc_hd__dfrtp_1 f1 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[1]));
  sky130_fd_sc_hd__dfrtp_1 f2 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[2]));
  sky130_fd_sc_hd__dfrtp_1 f3 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[3]));
  sky130_fd_sc_hd__dfrtp_1 f4 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[4]));
  sky130_fd_sc_hd__dfrtp_1 f5 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[5]));
  sky130_fd_sc_hd__dfrtp_1 f6 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[6]));
  sky130_fd_sc_hd__dfrtp_1 f7 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[7]));
  sky130_fd_sc_hd__dfrtp_1 f8 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[8]));
  sky130_fd_sc_hd__dfrtp_1 f9 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[9]));
  sky130_fd_sc_hd__dfrtp_1 f10 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[10]));
  sky130_fd_sc_hd__dfrtp_1 f11 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[11]));
  sky130_fd_sc_hd__dfrtp_1 f12 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[12]));
  sky130_fd_sc_hd__dfrtp_1 f13 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[13]));
  sky130_fd_sc_hd__dfrtp_1 f14 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[14]));
  sky130_fd_sc_hd__dfrtp_1 f15 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[15]));
  sky130_fd_sc_hd__dfrtp_1 f16 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[16]));
  sky130_fd_sc_hd__dfrtp_1 f17 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[17]));
  sky130_fd_sc_hd__dfrtp_1 f18 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[18]));
  sky130_fd_sc_hd__dfrtp_1 f19 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[19]));
  sky130_fd_sc_hd__dfrtp_1 f20 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[20]));
  sky130_fd_sc_hd__dfrtp_1 f21 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[21]));
  sky130_fd_sc_hd__dfrtp_1 f22 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[22]));
  sky130_fd_sc_hd__dfrtp_1 f23 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[23]));
  sky130_fd_sc_hd__dfrtp_1 f24 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[24]));
  sky130_fd_sc_hd__dfrtp_1 f25 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[25]));
  sky130_fd_sc_hd__dfrtp_1 f26 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[26]));
  sky130_fd_sc_hd__dfrtp_1 f27 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[27]));
  sky130_fd_sc_hd__dfrtp_1 f28 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[28]));
  sky130_fd_sc_hd__dfrtp_1 f29 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[29]));
  sky130_fd_sc_hd__dfrtp_1 f30 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[30]));
  sky130_fd_sc_hd__dfrtp_1 f31 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[31]));
  sky130_fd_sc_hd__dfrtp_1 f32 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[32]));
  sky130_fd_sc_hd__dfrtp_1 f33 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[33]));
  sky130_fd_sc_hd__dfrtp_1 f34 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[34]));
  sky130_fd_sc_hd__dfrtp_1 f35 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[35]));
  sky130_fd_sc_hd__dfrtp_1 f36 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[36]));
  sky130_fd_sc_hd__dfrtp_1 f37 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[37]));
  sky130_fd_sc_hd__dfrtp_1 f38 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[38]));
  sky130_fd_sc_hd__dfrtp_1 f39 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[39]));
  sky130_fd_sc_hd__dfrtp_1 f40 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[40]));
  sky130_fd_sc_hd__dfrtp_1 f41 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[41]));
  sky130_fd_sc_hd__dfrtp_1 f42 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[42]));
  sky130_fd_sc_hd__dfrtp_1 f43 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[43]));
  sky130_fd_sc_hd__dfrtp_1 f44 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[44]));
  sky130_fd_sc_hd__dfrtp_1 f45 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[45]));
  sky130_fd_sc_hd__dfrtp_1 f46 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[46]));
  sky130_fd_sc_hd__dfrtp_1 f47 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[47]));
  sky130_fd_sc_hd__dfrtp_1 f48 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[48]));
  sky130_fd_sc_hd__dfrtp_1 f49 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[49]));
  sky130_fd_sc_hd__dfrtp_1 f50 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[50]));
  sky130_fd_sc_hd__dfrtp_1 f51 (.CLK(clk), .D(d), .RESET_B(r), .Q(q[51]));
endmodule

ConceptWhy does the flow repair design rules before it repairs setup timing?

Electrical repairs change delays and can invalidate earlier setup workDesign rules are checked only once, at sign-off, so they come firstSetup repair would add more buffers than the area allowsDesign-rule repair also fixes every hold violation on the way

ConceptA net from an input port drives too much capacitance. Why can repair_design not resize its driver?

Resizing is allowed only for flops, never for buffersThe driver is outside the block; the SDC only models itA port can drive any load, so there is nothing to resizeThe library has no buffer stronger than a buf_1

ConceptWhy is the reset a high-fanout net that gets a plain buffer tree, while the clock gets clock tree synthesis?

The reset is asynchronous, so it has no timing checks at allBuffers on a reset net would reset the flops in the wrong orderClock skew moves every check; reset needs limits and a timed releaseThe reset changes too slowly for any tree to matter

ConceptA net of 0.19 pF is driven by a buf_1 inside the block. Which repair cannot be made with this library?

Resize the driver to a buf_4, which may drive moreSplit the loads behind two or three buffers placed near themResize the driver to a buf_8 and split off half the loadsResize the driver to a buf_32, twice the strongest buffer

Remember

Design rules are the library's electrical limits: max transition per pin, max capacitance per output, and max fanout when the SDC sets one.
repair_design fixes them by buffering (a buffer tree that splits the loads) and resizing (a stronger driver), using placement to estimate wires.
Close electrical rules and timing together; DRV limits and Liberty table coverage are distinct checks.
Reset and enable are the usual high-fanout nets; reset gets a buffer tree, and its recovery and removal checks still need watching after the repair.