wolfSSL is announcing wolfIP support for the STM32N6 series, starting with the NUCLEO-N657X0-Q development board (STM32N657X0H). The STM32N6 is ST’s first Cortex-M55 microcontroller, designed for high-performance edge AI workloads with a dedicated Neural Processing Unit (NPU). wolfIP provides a full TCP/IP stack with ping, TCP echo, and ARP on this new platform.
About the STM32N6
The STM32N6 is built around the Arm Cortex-M55 core running at 600 MHz currently but can be run at up to 800 MHz. It targets edge AI applications such as vision, audio classification, and anomaly detection. Unlike most STM32 parts, the N6 has no internal flash. All firmware resides on external NOR flash connected via the high-speed XSPI2 interface, with over 4.2 MB of on-chip SRAM available for code execution and data.
This flash-less architecture makes the STM32N6 a great fit for applications that need large, updateable firmware images without being constrained by internal flash size, while still benefiting from the performance of a modern Cortex-M55 core with Helium vector extensions.
wolfIP on the STM32N6
The wolfIP port runs as a fully self-contained bare-metal application with no external dependencies: no STM32Cube HAL, no CMSIS headers, no RTOS required. The Ethernet driver is shared across the STM32H5, STM32H7, and STM32N6 ports, with N6-specific adaptations for the GMAC v5.20 dual-channel DMA and the STM32N6 security architecture (RISAF, RIMC, RISC, SAU).
The port is loaded directly into AXISRAM via JTAG using OpenOCD, making the development cycle fast: build, flash to SRAM, and run in under two seconds. Ping latency is under 0.2 ms and the TCP echo server provides immediate response on port 7.
The binary comes in at approximately 25 KB, well within the 512 KB AXISRAM1 region.
The current port provides a ping (ICMP) and TCP echo server example. Future work includes TLS 1.3 support via wolfSSL, TrustZone integration, and booting from external XSPI flash via wolfBoot.
Tested Hardware
- Board: NUCLEO-N657X0-Q (STM32N657X0H, MB1940)
- PHY: LAN8742A (on-board, RMII at 100 Mbps)
- Build + Flash: make && bash flash.sh using OpenOCD with ST-Link V3
Source Code
The wolfIP STM32N6 port is available at: PR#85
If you have questions about any of the above, please contact us at facts@wolfssl.com or call us at +1 425 245 8247.
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