UCIe/D2D Post Si Validation Engineer

Job Description: D2D/UCIe Functional Validation Engineer

Role Overview

We are looking for a Die-to-Die (D2D)/UCIe Functional Validation Engineer with 3 to 8 years of experience in silicon validation, high-speed interface validation, firmware-based validation, and system-level debug.

The candidate will be responsible for validating UCIe-based die-to-die interfaces operating at various UCIe 1.1 Spec defined data rates on complex multi-die and chiplet-based SoC platforms. The role involves validation of the UCIe PHY, Adapter, protocol stack, sideband interface, link initialization, training, reliability mechanisms, power-management flows, and end-to-end data transfer between dies.

The engineer will develop and execute validation plans, create test cases, support pre-silicon and post-silicon bring-up, debug complex link failures, and collaborate with architecture, design, PHY, firmware, packaging, signal integrity, and platform teams.

The ideal candidate should have a strong understanding of high-speed serial or parallel interfaces, UCIe architecture, die-to-die communication, PHY training, firmware-controlled link initialization, and silicon debug methodologies.

Key Responsibilities

• Perform functional validation of UCIe-based D2D interfaces on pre-silicon and post-silicon platforms.
• Validate UCIe links operating at 8, 16, 24, 32 GT/s  etc., per lane across supported link widths and package configurations.
• Develop, enhance, and maintain validation test plans and test cases for the UCIe PHY, Adapter, protocol layer, sideband interface, and end-to-end data paths.
• Support silicon and platform bring-up, including reset sequencing, clock initialization, PHY initialization, link training, parameter exchange, transition to mission mode, and traffic enablement.
• Validate UCIe link initialization and training across all supported speeds, widths, lane configurations, voltage conditions, temperature conditions, and process corners.
• Verify speed negotiation, link-width negotiation, lane mapping, lane reversal, lane disablement, lane repair, spare-lane usage, and link retraining mechanisms.
• Validate UCIe protocol mappings such as PCIe, CXL, streaming, and raw-mode traffic, where applicable to the platform.
• Validate interfaces between the UCIe Adapter and protocol or logic layers, including RDI, FDI, or equivalent implementation-specific interfaces.
• Develop and execute end-to-end traffic tests between chiplets using register accesses, memory transactions, DMA traffic, streaming traffic, cache-coherent traffic, and platform-specific protocols.
• Validate bidirectional and simultaneous traffic across multiple D2D links and chiplets.
• Verify protocol reliability mechanisms, including CRC checking, retry, replay, error detection, error reporting, link recovery, and data integrity.
• Validate sideband communication, initialization messages, management transactions, reset handshakes, error notifications, and power-management messages.
• Validate link state transitions, including initialization, active operation, retraining, recovery, low-power entry and exit, reset, and link shutdown.
• Validate warm reset, cold reset, link reset, die reset, firmware restart, surprise reset, and error-recovery scenarios.
• Perform negative testing by injecting protocol, PHY, lane, CRC, timeout, malformed packet, retry, replay, and sideband errors.
• Validate link behavior under lane failures, marginal lanes, degraded channel conditions, clock disturbances, voltage variations, and thermal stress.
• Characterize link stability, BER, eye margins, timing margins, voltage margins, lane-to-lane skew, jitter tolerance, and long-duration reliability.
• Execute stress scenarios involving maximum bandwidth, bidirectional traffic, multi-link concurrency, repeated retraining, reset loops, power-state transitions, and thermal or voltage stress.
• Measure bandwidth, latency, protocol efficiency, utilization, retry overhead, and performance scaling across different speeds and link widths.
• Develop and debug low-level firmware for UCIe initialization, PHY configuration, link training, register programming, error injection, traffic generation, and status monitoring.
• Develop bare-metal tests and firmware-based validation sequences for early silicon bring-up.
• Develop automation scripts for test execution, configuration sweeps, register dumps, log parsing, failure detection, and result analysis.
• Debug silicon failures using firmware logs, PHY logs, protocol traces, register dumps, waveform captures, scan dumps, counters, and platform telemetry.
• Use oscilloscopes, BERTs, logic analyzers, protocol analyzers, JTAG debuggers, and other lab equipment to analyze D2D link behavior.
• Work closely with architecture, RTL design, verification, PHY, firmware, packaging, signal integrity, power, clocking, and platform teams to identify root causes and drive issues to closure.
• Participate in reviews of UCIe architecture, PHY behavior, Adapter functionality, protocol flows, register definitions, firmware sequences, and validation coverage.
• Create and maintain validation documentation, including test plans, test-case specifications, bring-up checklists, debug guides, issue reports, coverage reports, and execution summaries.
• Track validation progress, report risks and blockers, and support defect triage through Jira, Bugzilla, or equivalent issue-management systems.
• Improve validation infrastructure, automation frameworks, regression environments, debug tools, and coverage methodology.
  
  

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Accommodations at Arm

At Arm, we want to build extraordinary teams. If you need an adjustment or an accommodation during the recruitment process, please email accommodations@arm.com. To note, by sending us the requested information, you consent to its use by Arm to arrange for appropriate accommodations. All accommodation or adjustment requests will be treated with confidentiality, and information concerning these requests will only be disclosed as necessary to provide the accommodation. Although this is not an exhaustive list, examples of support include breaks between interviews, having documents read aloud, or office accessibility. Please email us about anything we can do to accommodate you during the recruitment process.

Hybrid Working at Arm

Arm’s approach to hybrid working is designed to create a working environment that supports both high performance and personal wellbeing. We believe in bringing people together face to face to enable us to work at pace, whilst recognizing the value of flexibility. Within that framework, we empower groups/teams to determine their own hybrid working patterns, depending on the work and the team’s needs. Details of what this means for each role will be shared upon application. In some cases, the flexibility we can offer is limited by local legal, regulatory, tax, or other considerations, and where this is the case, we will collaborate with you to find the best solution. Please talk to us to find out more about what this could look like for you.

Equal Opportunities at Arm

Arm is an equal opportunity employer, committed to providing an environment of mutual respect where equal opportunities are available to all applicants and colleagues. We are a diverse organization of dedicated and innovative individuals, and don’t discriminate on the basis of race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran.