lowRISC/opentitan
Oct 2024 – Jun 2025
8 Months active
Languages Used
SystemVerilogElHjsonMarkdownElispHCLSVGC
Technical Skills
Hardware DesignSystemVerilogVerificationCoverageCoverage AnalysisEmbedded Systems
Antonio Martinez Zambrana
PROFILE
Antonio Martinez Zambrana
Amz contributed to the lowRISC/opentitan repository by developing and enhancing hardware verification environments, focusing on modules like AON_TIMER and RV_TIMER. Over eight months, Amz delivered robust SystemVerilog and UVM-based testbenches, improved code organization, and expanded coverage through targeted regression and formal verification. Their work included optimizing interrupt timing, refining alert and ping handling, and modernizing device interfaces, all while maintaining thorough documentation and aligning testbenches with RTL changes. Amz also addressed CI stability and code quality, integrating Python scripting and coverage analysis to streamline simulation workflows. The depth of their contributions improved reliability, diagnosability, and maintainability across the codebase.
Overall Statistics
Feature vs Bugs
63%Features
Repository Contributions
204Total
Bugs
30
Commits
204
Features
50
Lines of code
13,841
Activity Months8
Your Network
108 people
Work History
June 2025
13 Commits • 2 Features
Jun 1, 2025June 2025: Delivered robustness and verification improvements in the opentitan codebase, with CI alignment for rv_plic. Focused on reliability, diagnosability, and CI stability, translating technical changes into clear business value for hardware/software integration.
13 Commits • 2 Features
Jun 1, 2025June 2025: Delivered robustness and verification improvements in the opentitan codebase, with CI alignment for rv_plic. Focused on reliability, diagnosability, and CI stability, translating technical changes into clear business value for hardware/software integration.
June 2025
May 2025
34 Commits • 9 Features
May 1, 2025May 2025 monthly summary for lowRISC/opentitan focused on RV_TIMER enhancements, DV modernization, FPV integration, and CI hygiene. Key outcomes include improved interrupt latency and responsiveness, modernized devmode interfaces with new skeletons, expanded testbench coverage, FPV corefile/sim_cfg integration, and robust SPI_DEVICE fixes. Documentation and revision updates complemented engineering work, while extensive Xcelium warning mitigations across DV suites reduced CI noise and improved test stability.
May 2025
34 Commits • 9 Features
May 1, 2025May 2025 monthly summary for lowRISC/opentitan focused on RV_TIMER enhancements, DV modernization, FPV integration, and CI hygiene. Key outcomes include improved interrupt latency and responsiveness, modernized devmode interfaces with new skeletons, expanded testbench coverage, FPV corefile/sim_cfg integration, and robust SPI_DEVICE fixes. Documentation and revision updates complemented engineering work, while extensive Xcelium warning mitigations across DV suites reduced CI noise and improved test stability.
April 2025
99 Commits • 22 Features
Apr 1, 2025April 2025 monthly summary for lowRISC/opentitan focusing on delivering robust alerting, timing accuracy, and DV/test quality improvements, while expanding testability and configuration capabilities. The work emphasizes business value through increased system reliability, better fault-detection, and maintainability across the DV/RTL stack.
99 Commits • 22 Features
Apr 1, 2025April 2025 monthly summary for lowRISC/opentitan focusing on delivering robust alerting, timing accuracy, and DV/test quality improvements, while expanding testability and configuration capabilities. The work emphasizes business value through increased system reliability, better fault-detection, and maintainability across the DV/RTL stack.
April 2025
March 2025
25 Commits • 10 Features
Mar 1, 2025March 2025 monthly summary for lowRISC/opentitan focused on robust timer verification, documentation, and observability improvements around the AON timer and related alert/ping infrastructure. The work delivered stronger developer onboarding material, deeper test coverage, and higher runtime reliability for critical security timers. Highlights include extensive AON timer documentation refresh with updated diagrams and theory of operation, refactors to the alert monitoring/handshake to enable correct sampling, and multiple bug fixes to synchronize TX/RX paths and ROM control sequencing. Expanded simulation readiness with RACL integration, non-RACL exclusions documentation, and sim config updates. Verification milestones progressed with a V3 verification stage and D3 design stage, accompanied by broader smoke regression coverage. Achieved measurable business value through improved maintainability, faster debugging, and increased confidence ahead of release.
March 2025
25 Commits • 10 Features
Mar 1, 2025March 2025 monthly summary for lowRISC/opentitan focused on robust timer verification, documentation, and observability improvements around the AON timer and related alert/ping infrastructure. The work delivered stronger developer onboarding material, deeper test coverage, and higher runtime reliability for critical security timers. Highlights include extensive AON timer documentation refresh with updated diagrams and theory of operation, refactors to the alert monitoring/handshake to enable correct sampling, and multiple bug fixes to synchronize TX/RX paths and ROM control sequencing. Expanded simulation readiness with RACL integration, non-RACL exclusions documentation, and sim config updates. Verification milestones progressed with a V3 verification stage and D3 design stage, accompanied by broader smoke regression coverage. Achieved measurable business value through improved maintainability, faster debugging, and increased confidence ahead of release.
February 2025
15 Commits • 1 Features
Feb 1, 2025February 2025 (lowRISC/opentitan): Delivered substantial enhancements to the Aon_timer verification environment, achieving higher reliability, faster validation cycles, and closer RTL/testbench alignment. The work focused on verification fidelity, test effectiveness, and robust bug fixes that reduce risk in upcoming firmware/RTL releases.
15 Commits • 1 Features
Feb 1, 2025February 2025 (lowRISC/opentitan): Delivered substantial enhancements to the Aon_timer verification environment, achieving higher reliability, faster validation cycles, and closer RTL/testbench alignment. The work focused on verification fidelity, test effectiveness, and robust bug fixes that reduce risk in upcoming firmware/RTL releases.
February 2025
January 2025
10 Commits • 3 Features
Jan 1, 2025January 2025 monthly summary for lowRISC/opentitan: Delivered critical reliability and verification enhancements, focusing on correctness, area optimization, and scalable verification. Key work includes bug fix in Prim_reg_cdc_arb to ensure acknowledgements are only emitted when matching requests and simplifying conditional paths, state-width reduction in Prim_reg_cdc_arb to shrink area with no functional changes, and a new Scoreboard verification framework with prediction support enabling centralized intr_state checks, a generic read-check hook, and prediction-based masking for improved verification (including aon_timer). Additionally, AON_TIMER verification improvements and testbench alignment were made, including RTL-consistent TB updates, new convenience cfg functions for reuse, and WKUP_CTRL documentation alignment. These efforts improved reliability, reduced silicon area, and strengthened verification coverage for critical timing and interrupt domains. Technologies exercised include Verilog/SystemVerilog, UVM-based verification, scoreboard techniques, and TB reusability.
January 2025
10 Commits • 3 Features
Jan 1, 2025January 2025 monthly summary for lowRISC/opentitan: Delivered critical reliability and verification enhancements, focusing on correctness, area optimization, and scalable verification. Key work includes bug fix in Prim_reg_cdc_arb to ensure acknowledgements are only emitted when matching requests and simplifying conditional paths, state-width reduction in Prim_reg_cdc_arb to shrink area with no functional changes, and a new Scoreboard verification framework with prediction support enabling centralized intr_state checks, a generic read-check hook, and prediction-based masking for improved verification (including aon_timer). Additionally, AON_TIMER verification improvements and testbench alignment were made, including RTL-consistent TB updates, new convenience cfg functions for reuse, and WKUP_CTRL documentation alignment. These efforts improved reliability, reduced silicon area, and strengthened verification coverage for critical timing and interrupt domains. Technologies exercised include Verilog/SystemVerilog, UVM-based verification, scoreboard techniques, and TB reusability.
December 2024
7 Commits • 2 Features
Dec 1, 2024December 2024 monthly summary for lowRISC/opentitan. Focused on strengthening AON timer testbench reliability, coverage, and correctness, with emphasis on CDC boundary handling and wakeup interrupt verification. Delivered CDC-aware intr_state tracking, CDC-boundary write synchronization, corrected prescale handling on wkup_ctrl, and expanded testbench coverage/configuration, including alert-test integration and coverage pruning. These changes improve validation fidelity, reduce risk of regressions in timer/interrupt paths, and streamline simulation workflows.
7 Commits • 2 Features
Dec 1, 2024December 2024 monthly summary for lowRISC/opentitan. Focused on strengthening AON timer testbench reliability, coverage, and correctness, with emphasis on CDC boundary handling and wakeup interrupt verification. Delivered CDC-aware intr_state tracking, CDC-boundary write synchronization, corrected prescale handling on wkup_ctrl, and expanded testbench coverage/configuration, including alert-test integration and coverage pruning. These changes improve validation fidelity, reduce risk of regressions in timer/interrupt paths, and streamline simulation workflows.
December 2024
October 2024
1 Commits • 1 Features
Oct 1, 2024October 2024: Delivered a SystemVerilog code organization improvement for the Aon_Timer module in opentitan by introducing the extern keyword for methods and constraints, decoupling declarations from definitions across the environment and sequence library DV files. This refactor enhances readability, maintainability, and testbench reliability, laying groundwork for safer future DV changes and faster onboarding of engineers. The change was implemented via commit 0579befeb205049ef6de301d8b84f24ad0367468 ([aon_timer, dv] Add extern keyword to methods/constraints). No major bugs were fixed this month; the focus was on strengthening the DV code structure to reduce cross-file regressions and simplify collaboration.
October 2024
1 Commits • 1 Features
Oct 1, 2024October 2024: Delivered a SystemVerilog code organization improvement for the Aon_Timer module in opentitan by introducing the extern keyword for methods and constraints, decoupling declarations from definitions across the environment and sequence library DV files. This refactor enhances readability, maintainability, and testbench reliability, laying groundwork for safer future DV changes and faster onboarding of engineers. The change was implemented via commit 0579befeb205049ef6de301d8b84f24ad0367468 ([aon_timer, dv] Add extern keyword to methods/constraints). No major bugs were fixed this month; the focus was on strengthening the DV code structure to reduce cross-file regressions and simplify collaboration.
Activity
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Quality Metrics
Correctness90.8%
Maintainability90.6%
Architecture87.8%
Performance85.0%
AI Usage20.0%
Skills & Technologies
Programming Languages
CElElispHCLHjsonMarkdownPythonSVGSystemVerilogTcl
Technical Skills
Checklist ManagementCode CoverageCoverageCoverage AnalysisDUT DebuggingDesign VerificationDevice DriversDiagrammingDigital DesignDocumentationEmbedded SystemsFPGA DevelopmentFPGA/ASIC SimulationFPVFormal Verification
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