Chip Design Hub

Introduction to RTL and High-Level Synthesis (HLS)

In today’s rapidly evolving semiconductor industry, optimizing design and development processes is paramount. As system-on-chip (SoC) and application-specific integrated circuit (ASIC) designs become increasingly complex, engineers are looking for ways to enhance productivity while maintaining high performance and low power consumption. One such advancement is the integration of Register Transfer Level (RTL) with High-Level Synthesis (HLS).

At the heart of this integration lies a dynamic collaboration between RTL design, IP (Intellectual Property) development, and HLS tools. PulseWave Semi, as a leading player in the semiconductor domain, offers cutting-edge solutions in RTL design and development. Understanding how RTL and HLS work together is essential for SoC and ASIC design engineers to stay ahead in the game.

What is RTL Design?

Register Transfer Level (RTL) design is the process of modeling the behavior of a digital circuit at the register transfer level, which describes the flow of data between registers and the operations performed on the data. RTL design forms the foundation of the digital design process, where hardware engineers describe the logical behavior of circuits, typically using hardware description languages like Verilog and VHDL.

RTL design focuses on the implementation of individual components of a system, ensuring they function correctly and interact as intended within the overall design. It allows for precise control over timing, resource allocation, and functional correctness, which is essential for creating custom hardware systems.

High-Level Synthesis (HLS) – An Overview

High-Level Synthesis (HLS) is a design process that automatically converts high-level algorithmic descriptions into RTL code. Rather than manually writing RTL code line by line, engineers can now describe their designs in high-level programming languages such as C, C++, or SystemC. HLS tools then generate the corresponding RTL code for implementation on an FPGA, ASIC, or SoC.

HLS is a revolutionary step in the design of hardware, providing a higher abstraction level for designers. It accelerates development cycles by reducing the time spent on manual coding and debugging. Additionally, HLS offers optimization features that can significantly enhance the performance and resource utilization of the generated RTL code, which is critical in areas such as multimedia processing, machine learning, and communications.

Benefits of Integrating RTL with High-Level Synthesis (HLS)

Integrating RTL with HLS brings several advantages to the design and development process, especially when it comes to SoC and ASIC design. The key benefits include:

1. Accelerated Design Cycles: With the traditional RTL design process, engineers often manually create complex code to describe hardware components, a process that can be time-consuming and error-prone. By using HLS, engineers can describe the high-level behavior of their system in a much more intuitive programming language, such as C++ or Python. HLS tools then automatically generate the RTL code, significantly reducing design time.

This acceleration of the design cycle is especially critical in competitive markets, where time-to-market is a key factor in business success.

2. Improved Design Efficiency: RTL design and IP development are complex and require a high degree of precision and expertise. However, with HLS tools integrated into the RTL workflow, design engineers can focus on high-level functionality rather than low-level implementation details. By automating the conversion from high-level descriptions to RTL, HLS streamlines the process and reduces the likelihood of introducing design flaws.

Furthermore, HLS tools can optimize the generated RTL code, ensuring that it meets performance targets, such as low latency, high throughput, and low power consumption, without requiring extensive manual tuning.

3. Easier Exploration of Design Space: In the traditional RTL design flow, exploring different design options and configurations could be cumbersome. With HLS, engineers can easily modify the high-level algorithm and let the HLS tools generate multiple versions of the RTL code, allowing them to quickly compare different designs. This design space exploration capability helps engineers find the most efficient solution in terms of power, performance, and area (PPA).

4. Reusability of High-Level Code: One of the significant advantages of HLS is the ability to reuse high-level code across different platforms and designs. Engineers can develop high-level algorithms once and generate RTL for different target platforms (FPGA, ASIC, etc.) by simply adjusting the HLS tool settings. This reuse reduces the overall development effort and enables faster iterations in SoC/ASIC development.

Additionally, it supports the development of IP cores, which can be reused in multiple projects, improving both productivity and consistency.

Challenges in Integrating RTL with HLS

While the integration of RTL with HLS offers significant benefits, there are challenges to be addressed:

1. RTL-HLS Translation Accuracy: The automatic translation from high-level code to RTL can sometimes result in inefficient RTL designs, especially if the high-level description does not map directly to hardware concepts. The design process may require fine-tuning to ensure that the generated RTL is optimized for the target hardware.

2. Limited Support for Certain Design Styles: While HLS is excellent for many types of designs, such as data-parallel applications, it may not be the best choice for all scenarios. Some complex hardware designs that require intricate control logic or specialized architectures might still need manual RTL coding.

3. Tool and IP Compatibility: Integrating RTL with HLS tools requires careful consideration of toolchain compatibility. HLS tools generate RTL code, which must be compatible with existing RTL designs, IP blocks, and synthesis tools. Ensuring that the generated RTL integrates smoothly with existing IP libraries is crucial for successful implementation.

Role of the RTL Design Engineer

In this evolving design paradigm, the role of the RTL design engineer is shifting. Rather than being solely responsible for writing low-level RTL code, RTL engineers now work alongside high-level algorithm designers and HLS tool specialists to ensure that the generated RTL meets the performance, power, and area requirements of the project.

RTL engineers play a vital role in the following:

• Verifying the correctness of the generated RTL: After HLS tools generate the RTL, the RTL engineer is responsible for verifying its correctness, ensuring that it functions as expected within the larger SoC or ASIC design.
• Optimizing the RTL: While HLS can automate much of the work, RTL engineers are still needed to fine-tune and optimize the RTL for specific hardware platforms. They focus on performance optimization, resource utilization, and ensuring the generated code meets timing constraints.
• Integrating IP blocks: RTL engineers must work with various IP cores developed within the organization or third parties. They ensure that these IP blocks integrate seamlessly with the generated RTL code and function as part of a larger SoC or ASIC design.

PulseWave Semi’s Contribution to RTL Design and HLS Integration

At PulseWave Semi, we understand the importance of integrating RTL design with High-Level Synthesis for the development of advanced SoC and ASIC designs. By adopting cutting-edge HLS tools and techniques, we empower our design engineers to deliver high-performance, power-efficient, and cost-effective solutions for a wide range of industries, including telecommunications, automotive, and consumer electronics.

Our commitment to innovation ensures that our clients stay ahead of the curve in the ever-evolving semiconductor landscape. PulseWave Semi’s team of expert engineers works seamlessly with clients to develop custom RTL code and IP cores that are optimized for HLS integration, providing an edge in both time-to-market and product quality.

Conclusion

The integration of RTL with High-Level Synthesis is revolutionizing the way SoC and ASIC designs are developed. By streamlining the process of translating high-level algorithms into efficient RTL code, PulseWave Semi is at the forefront of this transformation. As the industry moves toward more complex designs, the collaboration between RTL design engineers, IP developers, and HLS tools will continue to drive innovation, helping businesses create advanced, high-performance products.

For SoC/ASIC designers looking to stay competitive in today’s fast-paced environment, mastering the integration of RTL and HLS is no longer optional—it is essential. With PulseWave Semi’s expertise and commitment to excellence, you can ensure your next design project is both efficient and future-ready.