chieve these speeds, NetX takes advantage of a 100-Mbps Ethernet port that the STM32F207 and STM32F217 provide for very high-speed transfers. Generally, TCP/IP stacks are significantly less than 100% efficient, resulting in performance well below wire speed. Developers then have to choose a more powerful processor or exhaust a lower power unit to achieve maximum network performance. In contrast, NetX Duo not only achieves 93–95% of wire speed on the STM32 processor, but does so using only 21–34% of the processor’s CPU cycles.
Such performance is achieved using the STM32F2xx ART Accelerator and the dedicated Ethernet MAC DMA connected to the 7-layer multi AHB bus matrix. This frugal use of CPU cycles is outstanding, freeing up the Cortex-M3-based processor for many other product functions that can run simultaneously without slowing network performance. Because of this, the inexpensive STM32F2xx processor can deliver maximum processing and connectivity, dropping design costs.
“Not all TCP/IP stacks are equal,” confirmed William E. Lamie, President of Express Logic. “In addition to some stacks performing better than others, some also help achieve lower development costs and faster time to market. To best meet their needs, developers should focus on which stacks are optimized to get the most out of their hardware. NetX Duo delivers outstanding performance on STMicroelectronics’ STM32F217, warranting significant consideration by the performance-conscious developer.”
“Combined with the NetX Duo software solution, the STM32 F2 Series demonstrates outstanding performance while maintaining free CPU and system bandwidth for customers to put more value in their applications,” said Michel Buffa, General Manager of ST’s Microcontroller Division. “Customers looking for even more performance have a pin-to-pin and software-compatible upgrade path with the STM32 F4 Series, the world’s highest performance ARM Cortex-M MCU.”
Express Logic’s IPsec for NetX Duo further speeds secure connectivity. IPsec automatically takes advantage of STM32F217’s hardware crypto acceleration to offload the extensive calculations involved in 3DES or AES encryption. With SHA-1 and MD5 authentication primarily performed by STM32F217’s hardware, developers can implement secure functionality without sacrificing application performance.
NetX Duo performance was measured using iperf, the open-source benchmark tool that has become the industry standard for measuring network throughput. For benchmarking, iperf runs on a Windows host connected to an STMicroelectronics STM3221G-EVAL target board via the Ethernet. The iperf TCP and UDP results were served by NetX Duo as a Web page and displayed by Microsoft Internet Explorer on the host.
Shipping and Availability
NetX Duo is available in full source code form, royalty free, with project licenses starting at $18,750.