WIZnet TOE(TCP/IP Offload Engine)

WIZnet TOE (TCP/IP Offload Engine) is a core technology of the WIZnet Ethernet solution implemented in hardware to efficiently process TCP/IP network communications. Internally, the TOE consists of a TCP/IP hardware stack for accelerating network protocol processing and a control system for operation settings and status checking. Processed data is automatically stored in allocated memory. The essence of TOE is to support fast and stable network communications in embedded systems without allocating additional resources or burdening performance.

Key Features of WIZnet Ethernet Chip

• Supports TCP/IPv4v6 stack: Supports fast 100/10 Ethernet communication through a hardware-based TCP/IPv4v6 stack (only W6100).
• Low-cost IoT application construction: Built-in MACPHY with a TCP/IPv4v6 Stack, enabling the construction of low-cost IoT solutions in conjunction with low-spec embedded systems.
• Compatibility with various hardware platforms: Supports convenient development with compatibility with many open-source platform boards, such as Arduino and ARM mbed.

Comparison between TOE and Software TCP/IP Stack 

When using a software-based TCP/IP stack, all resources used for network communication are provided by the embedded system. Since all packet processing is independently done by the embedded system from user applications, the system's performance directly determines the network performance, which can be significantly affected by the operational application. 

In contrast, the TOE processes the TCP/IP stack of packets through separate resources. Therefore, the system only receives processed data and processes it in the application, reducing the load and complexity associated with network use. Moreover, the hardware TCP/IP stack ensures a consistent transmission speed regardless of changes in the network environment.

Software TCP/IP vs. Hardware TCP/IP

Performance tests using iperf in 100M and 10M network bandwidths showed significant performance improvement when using TOE compared to SW TCP/IP. (Selected low-spec embedded system platform boards widely used in Ethernet solutions)

Conclusion

Embedded platform boards using WIZnet TOE demonstrated superior network performance and significantly reduced system load compared to Software TCP/IP. While Software TCP/IP, being an open library, offers the advantage of allowing diverse developments by users, it might not be suitable for quickly and easily constructing Ethernet solutions. WIZnet TOE solutions are hardware-based, making setup and control simple, and they provide various examples based on open-source platform boards like ST Nucleo, Arduino, and Raspberry Pi Pico. In summary, utilizing WIZnet TOE offers higher network performance, reduced load, quick development, and convenience. SW TCP/IP can be used when developers want more software control, but a more robust embedded system is needed for high performance and reduced load.