Taisil Micro strengthens R&D to fill the gap in China's high-end MCU chips

Recently, China's leading MCU chip manufacturer, Taishi Micro, announced the completion of nearly RMB 300 million in A+ round of financing. This round of financing provided Taishi Micro with sufficient funds for its planned comprehensive MCU layout, and also further opened up relevant resources from the upstream and downstream of the industrial chain, accelerating Taishi Micro's development pace into the leading domestic semiconductor companies.

At present, the industry generally uses read-only memory images with dynamic passwords to develop some startup upgrade code logic with relatively high security requirements, and burns them in at one time during tape-out. However, in the process of chip development, it is often necessary to gradually upgrade as the chip is mass-produced and applied. The original burned code logic has been solidified, making it difficult to modify and further upgrade, and the solidified code logic has been fixed, which also has the risk of leakage. Therefore, there is an urgent need for an MCU chip with high security and the ability to upgrade and modify some logic.

To this end, Taishi Micro applied for an invention patent on June 30, 2020 entitled "A method for achieving MCU chip security by using ROM combined with storage islands" (application number: 202010606503.9), and the applicant was Shanghai Taishi Microelectronics Co., Ltd.

Figure 1 MCU chip security method logic flow chart

Figure 2 MCU chip security method module flow chart

As shown in Figures 1 and 2, a method for realizing MCU chip security by using a traditional ROM combined with a storage island includes an MCU module, and the MCU module includes a storage island unit and a ROM startup unit. The method also includes the following steps: first, a security program is written, and the security program is encrypted by a private key; then the storage island unit stores the security program encrypted by the private key; then the ROM startup unit responds to an external startup signal and pairs the public key with the security program encrypted by the private key; if the pairing is successful, the ROM startup unit reads the security program, and then the ROM startup unit starts; if the pairing is unsuccessful, the ROM startup unit cannot read the security program, and then the ROM startup unit cannot start.

By setting up a storage island unit in the MCU module, the burning module can be used to enter, upgrade and replace the content of the storage island unit, which solves the defect that the traditional method of using only ROM cannot be expanded secondary. In addition, the content passed to the storage island unit by the burning module is also encrypted by RSA asymmetric encryption. That is, the cloud service module encrypts the content with a private key, and after passing it to the storage island unit, the encrypted content can only be decrypted by the user using the correct public key. After decryption, the ROM startup unit can read the content in the storage island unit, and then the MCU chip can start normally. This can prevent illegal elements from stealing or cracking the program, and eliminate the breeding of such illegal activities from the root.

This embodiment also includes a cloud service module, which can save private keys and use private keys to encrypt security programs to form ciphertext. The user compiles plain text through the IDE on the PC side, and then passes the plain text to the cloud server. The cloud server selects different secret keys according to the specific chip, and then uses the secret key to encrypt the plain text to form ciphertext. The ciphertext is then passed to the burning module, and the secret key is not passed. The cloud service module manages the secret key. As long as the key is not leaked, even if the criminals get the public key, they cannot crack the ciphertext, and the cracking program cannot run normally, which further protects the rights and interests of software developers.

In short, TaiSilicon's MCU chip security method patent improves security by separately dividing the storage island unit in the MCU module so that the encrypted content can only be decrypted by the user using the correct public key, while also enabling the storage island unit to be upgraded and modified.

As China's leading high-performance dedicated MCU chip supplier, Taishi Micro is committed to the research and development of IoT application chips. In the future, Taishi Micro will continue to consolidate the research and development of my country's dedicated MCU chips, continuously accelerate product iteration and upgrade, and actively promote the layout in the consumer electronics, medical and automotive markets.