๐Ÿ“‹PREREQUISITE STAGE 01 HANDOVER

01. System Spec & Customer Handover Protocol

Before physical logic synthesis, inspect what customer input files (.sdc, .upf, .lef, .lib, .pdf), constraints, and PDK deliverables are shared with designers, featuring the IoT-Sense-RV32 SoC benchmark case study & battery calculator.

STAGES 01 TO 06

RTL-to-GDSII Automated EDA Pipeline

Explore every physical design stage from HDL synthesis to signoff GDSII layout. Click on any stage below to inspect inputs, outputs, commands, and QoR statistics.

STAGE 01

RTL Synthesis

Yosys
Verilog to Netlist

Translates high-level Verilog/SystemVerilog RTL into a technology-mapped gate-level netlist using standard cell target libraries (.lib).

INPUT ARTIFACTS
  • design.v
  • sky130_fd_sc_hd.lib
  • constraints.sdc
OUTPUT ARTIFACTS
  • synthesis.v
  • synthesis.stat.json
QoR METRICS
area124,500 ยตmยฒ
cells14,820 gates
runtime42s
EXECUTION COMMAND
$ yosys -import -script synth_sky130.tcl
STAGE 02

Floorplan & PDN Grid

OpenROAD FP
Die Bounds & Power Rings

Establishes die core aspect ratio, places SRAM macro blocks, defines IO pins, and generates the Power Distribution Network (PDN) metal mesh.

INPUT ARTIFACTS
  • synthesis.v
  • sky130.lef
  • tech.lef
OUTPUT ARTIFACTS
  • floorplan.def
  • pdn.def
QoR METRICS
dieSize1.2mm x 1.2mm
ioPins128 pins
pdnIRDrop12 mV max
EXECUTION COMMAND
$ openroad -exit floorplan.tcl
STAGE 03

Global & Detailed Placement

RePlAce / OpenROAD
Standard Cell Positioning

Performs electrostatics-based analytical global placement followed by legalizer and detailed placement to minimize wirelength & congestion.

INPUT ARTIFACTS
  • floorplan.def
  • sky130_fd_sc_hd.lef
OUTPUT ARTIFACTS
  • placed.def
  • congestion_heatmap.png
QoR METRICS
utilization68.4%
HPWL4.12 meters
overflow0.00%
EXECUTION COMMAND
$ openroad -exit placement.tcl
STAGE 04

Clock Tree Synthesis (CTS)

TritonCTS
Clock Skew & Buffer Tree

Constructs balanced clock tree distribution network using buffer insertion to minimize clock latency, skew, and hold time violations.

INPUT ARTIFACTS
  • placed.def
  • clock_tree.sdc
  • clk_buffers.lib
OUTPUT ARTIFACTS
  • cts.def
  • cts_skew.rpt
QoR METRICS
maxSkew34 ps
latency420 ps
clkBuffers342 cells
EXECUTION COMMAND
$ openroad -exit cts.tcl
STAGE 05

Global & Detailed Routing

FastRoute / TritonRoute
Metal Interconnect Trace

Generates detailed track assignment across metal layers (Met1 to Met5) while enforcing strict design rule checking (DRC) & antenna rules.

INPUT ARTIFACTS
  • cts.def
  • routing_guides.guide
OUTPUT ARTIFACTS
  • routed.def
  • spef_parasitics.spef
QoR METRICS
drcViolations0
metalLayers5 Layers
wireLength6.8m
EXECUTION COMMAND
$ openroad -exit detailed_route.tcl
STAGE 06

Signoff STA & GDSII Streaming

OpenSTA & KLayout
Timing & Tapeout File

Executes multi-corner Static Timing Analysis (STA), crosstalk parasitic delay calculation, and streams out final GDSII/OASIS layout format.

INPUT ARTIFACTS
  • routed.def
  • spef_parasitics.spef
  • sky130.lib
OUTPUT ARTIFACTS
  • chip_final.gds
  • sta_wns_tns.rpt
QoR METRICS
WNS+0.042 ns
TNS0.00 ns
tapeoutStatusPASS
EXECUTION COMMAND
$ klayout -b -r export_gds.py