Enhancing FPGA Prototyping: From Flexible Interfaces to Efficient Debugging

[AmandaK]

Introduction:

Prototyping is a crucial stage in validating SoC designs. By implementing prototyping on FPGAs, developers can begin software development and system validation long before the final hardware is ready. However, ensuring that the software developed on the prototyping platform can seamlessly transition to the final silicon and complete the bring-up process—where the system is fully operational—remains a significant challenge for development teams.

To overcome this challenge, while FPGA prototyping offers high performance and the ability to simulate real-world chip environments, meeting customer demands for shorter development cycles requires additional flexibility. Tools such as flexible daughter boards, speed adapters solutions, AXI co-simulation software, and optimized I/O partitioning play a critical role in achieving this goal. These tools provide a realistic environment for data interaction during software development and significantly accelerate the hardware/software bring-up process. As such, when selecting a commercial prototyping platform, the diversity and flexibility of available resources become key factors in improving verification efficiency.

1. How to Accelerate Prototyping?

The bring-up phase is a critical part of the prototyping process, involving a series of operations from hardware configuration and basic functionality verification to complex system debugging. It is more than just establishing hardware connections; it includes software execution, design loading, and error debugging. The ultimate goal is to ensure the system runs smoothly under expected conditions, paving the way for further functional testing and performance evaluation.

Several key factors contribute to a faster bring-up process:

Flexible Interfaces: For rapid deployment, flexible interfaces support connections to external devices. Daughter boards act as core components, enabling interaction between the prototype system and external hardware. These boards support various communication protocols such as MIPI, DDR4, and PCIe, catering to various application scenarios. By configuring daughter boards flexibly, development teams can quickly establish interfaces that mimic real-world environments, speeding up system validation.

• Speed adapters Solutions & IP Kits: Speed adapters solutions, along with associated IP development kits, are essential for coordinating data transmission between high-speed and low-speed devices, ensuring stable and seamless communication. These solutions adapt the prototype system to the actual application environment, enhancing the reliability of the entire prototyping system through efficient data handling mechanisms.
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• AXI Co-Simulation Software & Reference Designs: Beyond hardware support, AXI co-simulation software and reference designs are pivotal in fast deployment. The software facilitates efficient data transfer and processing, helping developers simulate and validate designs in environments that closely resemble the final silicon performance. Reference designs offer proven, ready-to-use solutions, reducing the need for time-consuming custom development. This combination of tools greatly boosts productivity, helping development teams meet verification goals more efficiently and quickly generate the required waveform data (Fast Time to Waveform).
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• Optimized I/O Partitioning: In large-scale SoC designs, partitioning remains a major challenge when loading designs. This means the system must provide abundant I/O interfaces and high-speed SerDes links for interconnecting partitioned components and connecting peripherals.

1. S2C Prodigy Prototyping Solutions

S2C’s Prodigy Prototyping Solutions offer a complete toolkit to address the challenges of FPGA-based prototyping, including flexible interfaces, speed adapters solutions, and advanced software tools that boost verification efficiency.

• Daughter Boards:

S2C daughter boards offer flexible interfaces between the prototyping system and the actual chip environment. These boards support various communication protocols, including MIPI for multimedia interfaces, DDR4 for SoC hardware/software integration, and PCIe for storage and networking needs. The flexibility of these daughter boards ensures that the prototype system can emulate real-use environments, enabling developers to quickly adapt to different application scenarios and accelerate the deployment of the prototyping system.

Unlike the fixed interfaces on many FPGA vendor boards or self-developed boards, which can reduce available IO pins for user designs, S2C Prodigy Prototyping Solutions offer a broad range of pre-validated external daughter boards that cover multiple protocols, including ARM processor interfaces, embedded modules, and multimedia modules. These pre-tested boards reduce development risk and are designed to meet industry standards for chip interfaces such as USB, HDMI, PCIe, Ethernet, and DDR. For instance, S2C's Prodigy three-channel RGMII/GMII PHY interface module, rigorously tested to run at over 125MHz, ensures stable gigabit Ethernet performance. With automated detection capabilities and integrated I/O voltage protection, these solutions further reduce the risk of hardware damage and achieve remote testing for global teams.

• Speed adapters Solutions:

S2C’s speed adapters solutions and IP modules ensure smooth data transmission between the prototype system and low-speed external devices. These solutions support flexible high-speed transmission protocol conversion, maintaining consistent system performance in real-world applications. In large-scale SoC designs, high-speed interfaces such as PCIe Gen3/Gen4 may need to run at reduced speeds during FPGA prototyping due to process limitations. S2C offers hardware-based and soft-core IP-based speed adapters solutions to adapt these high-speed interfaces, ensuring stable communication during the prototyping phase.

Additionally, the validation of advanced memory controller IPs, such as LPDDR4/5 and HBM2E/3, presents significant challenges during FPGA-based prototyping. Due to the newer nature of these standards, most FPGA vendors may not provide suitable PHY solutions, making it difficult to validate these memory controllers. S2C offers targeted solutions to address these challenges. For instance, a customer using an LPDDR4 memory controller in their design faced challenges in validating it due to the lack of FPGA-based LPDDR4 PHY IP. By utilizing S2C’s DFI-based memory controller IP solution, the customer successfully validated the LPDDR4 controller by interfacing with the FPGA vendor’s DDR4 memory controller, overcoming the verification hurdle.

• AXI Co-Simulation for Debugging:

Prototyping systems based on FPGA operate at speeds and precision levels close to the actual scenario, making them essential for verifying complete chip functionality and early-stage software development. S2C's ProtoBridgeTM software, utilizing the AXI-4 bus protocol and proprietary technology, enables high-throughput data exchange between the FPGA and the PC host. This allows developers to perform early software debugging and validation in an environment that closely resembles the actual chip’s performance, significantly reducing the effort required after the chip is fabricated and improving design migration efficiency.

• I/O Optimization for Partitioning:

Effective I/O management in large-scale SoC designs is crucial, as partitioning requires iterative mapping of design elements and constant correction of RTL or software-level errors for optimal system performance.

S2C’s Player Pro – CompileTime (PPro-CT) tool addresses these challenges with a streamlined approach. It provides an intuitive GUI that guides users through each compilation step while automating the ECO process with TCL scripting. Particularly in the I/O pin assignment, PPro-CT integrates a library that automatically maps the I/O configurations of S2C’s daughter boards, reducing errors and improving efficiency.

Traditional I/O layouts limit system scalability, but PPro-CT’s SerDes TDM mode effectively doubles cascading capacity, breaking through I/O limitations. This enables the validation of larger-scale designs and allows development teams to handle more complex projects, accelerating the overall prototyping process.

1. Conclusion:

Successful prototyping relies on the integration of several key elements. Flexible daughter boards ensure smooth external interface interaction, while speed adapters IP coordinates efficient data transfer between devices. With ProtoBridgeTM software, S2C’s Prodigy Prototyping Solutions support effective software debugging in environments close to actual chip conditions and I/O optimization with tools like PPro-CT enhances partitioning efficiency. S2C’s solutions—featuring over 90 pre-validated daughter boards and accessories—enable developers to rapidly set up prototyping deployment and meet various project requirements, reducing development risk, saving engineering resources, and accelerating time to market.