STC is an MCU based on 5 1 kernel, which is said to be developed in the United States, branded in Chinese mainland and produced in Taiwan Province Province.

STC series single chip microcomputer is produced by stmicroelectronics Company.

STC series MCU is produced by stmicroelectronics Company, and represented by Hongjing Company in mainland China. Stmicroelectronics, namely stmicroelectronics Company, was born after the merger of Italian SGS Microelectronics Company and French Thomson Microelectronics Company in June 1987. 1May, 998, the company was transformed from SGS Thomson.

(SGSTHOMSON) Microelectronics Company changed its name to stmicroelectronics Company, referred to as ST Company.

You can't say for sure now anyway. The lineage is unknown.