Among the many wireless communication standards, Wi-Fi is undoubtedly a communication standard that is very popular and used, especially in home and indoor environments. Nuvoton Technology is based on this general use scenario, especially in cooperation with module manufacturers to build a series of Secure Wi-Fi communication modules with TrustZone function based on the Arm® Cortex®-M23 core. The product series is expected to be officially launched in the second half of this year to provide services to the market. 

First, briefly introduce the Nuvoton M23 core products, M261, and M2354. Both of them are MCUs with Cortex®-M23 as the core. The difference is that M261 does not have the power of the hardware TrustZone, and the capacity of Flash memory and SRAM is small, and the security functions included are not so many. Still, the use cost (selling price) is relatively low. After all, the added function requires cost. In addition to the hardware of TrustZone, M2354 also adds security features at the physical level of the chip, including electromagnetic leakage analysis of cryptographic hardware accelerators (AES, RSA, ECC) and secure key storage area (Secure Key Store).

Furthermore, whether M261 or M2354 can support secondary development, it also has the Root-of-Trust feature with a built-in Secure Boot function. Moreover, because Nuvoton's Secure Boot can easily support secure firmware updates (FOTA), it has safety assurance for an application system. Finally, it is well integrated with the communication function of the wireless communication module itself. 

Secondly, compared to traditional Wi-Fi SoC (System-on-Chip) or modules, Nuvoton's Wi-Fi modules can provide some customized options. This approach has great flexibility benefits, especially for IoT applications. On the one hand, there are a small number of diverse phenomena of the Internet of Things at this stage, security considerations, and special interface requirements, such as the 5V power supply requirements of connected home appliances, etc. So we provide options similar to the following for customers to choose: 

• M261

• M2354

Secondly, considering the actual application scenarios, if the customer's module needs to have a security key or a certified certificate for burning, Nuvoton can provide this service because of its own security key injection environment. It can save customers from looking for the security key burning environment by themselves. The Wi-Fi module they get is a secondary development component with security identification and security functions. It can easily make the designed devices have secure connecting to the Internet and save you the extra burden for the unique networking and security requirements. 

Finally, let's talk about the benefits of secondary development. Suppose independent software developers can use Nuvoton M2354 microcontroller-based built-in TrustZone, XOM technology, or M261 internal XOM (eXecute-Only Memory) microcontroller with pre-loaded embedded software. In that case, the risk of the software being copied or misused can be eliminated. Because at this time, the software supplier no longer sells copies of the software but instead sells a physical microcontroller with embedded software or a secure wireless communication functional module as described in this article.