YosysHQ/yosys
Nov 2024 – May 2026
5 Months active
Languages Used
C++SystemVerilogVerilog
Technical Skills
Digital DesignHardware Description Language SynthesisHardware DesignVerilog/SystemVerilogFPGA DevelopmentVerilog HDL
Patrick Urban
PROFILE
Patrick Urban
Contributed to the YosysHQ/yosys repository by developing and refining hardware synthesis features and stability improvements for FPGA design flows. Focused on enhancing the gatemate synthesis path, this work included implementing robust handling of multiplexers and BRAM inputs using Verilog and SystemVerilog, which reduced timing errors and improved netlist reliability. Delivered configurable SERDES modules and introduced scopename attributes for finer netlist control, enabling more flexible and traceable synthesis. Addressed critical bugs affecting data integrity and timing determinism, applying targeted C++ and HDL changes. The approach emphasized maintainability, precise debugging, and alignment with established synthesis flows to support downstream hardware verification.
Overall Statistics
Feature vs Bugs
40%Features
Repository Contributions
5Total
Bugs
3
Commits
5
Features
2
Lines of code
289
Activity Months5
Your Network
87 peopleWork History
May 2026
1 Commits • 1 Features
May 1, 2026Month: 2026-05 — Focused on enhancing synthesis flexibility and traceability in YosysHQ/yosys. Delivered a targeted feature that empowers users with finer control over netlist scoping during synthesis, enabling customization and easier debugging while preserving performance. No major bugs fixed this month; ongoing maintenance and quality improvements remain a priority.
1 Commits • 1 Features
May 1, 2026Month: 2026-05 — Focused on enhancing synthesis flexibility and traceability in YosysHQ/yosys. Delivered a targeted feature that empowers users with finer control over netlist scoping during synthesis, enabling customization and easier debugging while preserving performance. No major bugs fixed this month; ongoing maintenance and quality improvements remain a priority.
May 2026
October 2025
1 Commits
Oct 1, 20252025-10 monthly summary for YosysHQ/yosys focused on stabilizing high-speed SERDES operation. Key delivery: SERDES CDR parameter stabilization in the gatemate module to fix incorrect RX_CDR_TRANS_TH and RX_CDR_LOCK_CFG values, preventing potential data errors due to misconfiguration. Implemented via commit 14c1802b0170df13fe7fd5b6a732721c1f94afa4. Overall impact: increased reliability of the SERDES path, reduced field risk, and improved production stability. Technical achievements: HDL parameter tuning, targeted debugging of the gatemate module, and Git-based patching across the repository. Business value: stronger data integrity for high-speed IO, lower maintenance costs, and a safer foundation for future SERDES enhancements.
October 2025
1 Commits
Oct 1, 20252025-10 monthly summary for YosysHQ/yosys focused on stabilizing high-speed SERDES operation. Key delivery: SERDES CDR parameter stabilization in the gatemate module to fix incorrect RX_CDR_TRANS_TH and RX_CDR_LOCK_CFG values, preventing potential data errors due to misconfiguration. Implemented via commit 14c1802b0170df13fe7fd5b6a732721c1f94afa4. Overall impact: increased reliability of the SERDES path, reduced field risk, and improved production stability. Technical achievements: HDL parameter tuning, targeted debugging of the gatemate module, and Git-based patching across the repository. Business value: stronger data integrity for high-speed IO, lower maintenance costs, and a safer foundation for future SERDES enhancements.
April 2025
1 Commits
Apr 1, 2025April 2025 monthly summary for YosysHQ/yosys. Focused on robustness of BRAM handling in the gatemate module to reduce timing-related errors. Key accomplishment: BRAM input stabilization by padding unused BRAM inputs with 'bx' to explicitly define all BRAM inputs, preventing undefined signals and lowering Critical Path Error (CPE) incidence. The change is committed in 6d575918fc2bbaff41efb41e8a98ad872ebeaf13 ('gatemate: Set unused BRAM inputs to 'bx'). Impact: improved synthesis reliability and timing determinism for BRAM paths, reducing CI/test noise and enabling more deterministic hardware flows. Technologies/skills demonstrated: HDL signal handling, patching BRAM input handling, code maintenance and version control discipline in a critical path area.
1 Commits
Apr 1, 2025April 2025 monthly summary for YosysHQ/yosys. Focused on robustness of BRAM handling in the gatemate module to reduce timing-related errors. Key accomplishment: BRAM input stabilization by padding unused BRAM inputs with 'bx' to explicitly define all BRAM inputs, preventing undefined signals and lowering Critical Path Error (CPE) incidence. The change is committed in 6d575918fc2bbaff41efb41e8a98ad872ebeaf13 ('gatemate: Set unused BRAM inputs to 'bx'). Impact: improved synthesis reliability and timing determinism for BRAM paths, reducing CI/test noise and enabling more deterministic hardware flows. Technologies/skills demonstrated: HDL signal handling, patching BRAM input handling, code maintenance and version control discipline in a critical path area.
April 2025
January 2025
1 Commits • 1 Features
Jan 1, 2025January 2025: Delivered extensible CC_SERDES configuration and clearer port naming in YosysHQ/yosys, enabling more flexible gatemate SERDES deployments with improved maintainability and reduced configuration errors.
January 2025
1 Commits • 1 Features
Jan 1, 2025January 2025: Delivered extensible CC_SERDES configuration and clearer port naming in YosysHQ/yosys, enabling more flexible gatemate SERDES deployments with improved maintainability and reduced configuration errors.
November 2024
1 Commits
Nov 1, 2024Month: 2024-11. Focused on stabilizing the gatemate synthesis path in Yosys, delivering a critical bug fix and reinforcing the robustness of the synthesis flow. Highlights include ensuring multiplexers are mapped before optimization, preventing unmapped multiplexers, and improving overall reliability for downstream optimization passes. This contributes to more predictable hardware results and reduces rework in verification downstream.
1 Commits
Nov 1, 2024Month: 2024-11. Focused on stabilizing the gatemate synthesis path in Yosys, delivering a critical bug fix and reinforcing the robustness of the synthesis flow. Highlights include ensuring multiplexers are mapped before optimization, preventing unmapped multiplexers, and improving overall reliability for downstream optimization passes. This contributes to more predictable hardware results and reduces rework in verification downstream.
November 2024
Activity
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Quality Metrics
Correctness86.0%
Maintainability90.0%
Architecture84.0%
Performance72.0%
AI Usage20.0%
Skills & Technologies
Programming Languages
C++SystemVerilogVerilog
Technical Skills
C++ developmentDigital DesignFPGA DevelopmentHardware Description Language SynthesisHardware DesignVerilogVerilog HDLVerilog/SystemVeriloghardware designsoftware synthesis
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