Simplifying Dual-End MIPI I3C® Logic Translator Validation Without the Complexity

The advancement of technology and its applications in domains like automotive ADAS, wearable sensor fusion, and modular industrial systems has led to tighter integration of sensors and controllers within electronic systems. This evolution demands high-speed, multi-device communication over compact PCBs, often through a single communication bus.  

While protocols like MIPI I3C® are designed to support high-bandwidth, low-power communication, they come with physical layer limitations on how many devices can be connected to a single bus. Logic translators overcome this constraint by isolating a group of devices into a secondary bus while maintaining seamless communication with the main bus. However, validating a MIPI I3C® logic translator is a nuanced process with unique considerations.  

This case study delves into the customer’s specific validation needs, the challenges posed by this unique use case, and how Soliton helped simplify the process and ensure precise protocol compliance. 

Breaking Down the Customer’s Validation Needs 

One of our customers, a prominent semiconductor company, developed a I3C logic translator to bridge between the main controller and additional target devices. Unlike validating a standalone MIPI I3C® controller or target device, the validation of a logic translator introduces added complexity. Here, both the input (controller-facing) and output (target-facing) interfaces must be tested simultaneously. This dual-end validation posed significant challenges in terms of setup, coverage, and precision. 

Achieving thorough validation meant addressing the following core requirements: 

• Bi-directional Protocol Validation 

Conduct protocol transactions and validate both, the controller-facing and target-facing interfaces simultaneously. This required emulating protocol activity on one side, capturing and decoding it on the other, and verifying end-to-end compliance with MIPI I3C® specifications. Given that most tools support only one role at a time, this dual-role emulation and synchronized validation setup added a layer of complexity that traditional methods struggled to manage efficiently. 

• Maintaining Signal Integrity Across Interfaces 

Sweeping, measuring, and correlating key bus parameters, such as voltage, timing, and frequency, across operational ranges was essential to evaluate the translator’s performance and ensure compliance. It was equally important to confirm that the data maintained its fidelity, free from any signal distortion. Meeting this requirement involved developing custom test scripts to coordinate voltage and timing variations at each end and manually collecting the resulting data. 

• Precise Propagation Delay Measurement 

Propagation delay refers to the inherent latency introduced as signals pass through the logic translator. Even a few nanoseconds of propagation delay can disrupt signal alignment in timing-sensitive I3C systems. To prevent issues such as clock skew, data corruption, or false failures, the customer needed to measure this delay with high precision and ensure it stayed within the strict limits defined by the specifications. 

Architectural diagram of the validation setup before PVS

Legacy validation setups involved multiple instruments and complex manual coordination to achieve dual-end emulation. Off-the-shelf tools were not readily equipped to model the translator’s behavior, and custom test benches often demanded considerable time and engineering effort. To address these challenges efficiently, the customer required a unified, protocol-aware validation environment that could deliver thorough, specification-compliant results. 

Enabling Validation through a Scalable Tool Adapted to Accommodate the Logic Translator Test Scenario 

Soliton addressed the customer’s unique requirement with the MIPI I3C® Protocol Validation Suite that could accommodate the customer’s unique validation scenario involving a logic translator. By extending existing capabilities to support dual-end emulation, precise timing measurements, and compliance coverage, PVS enabled an efficient, structured validation process tailored to the customer’s needs.