Biren Technology, a Shanghai chip design start-up seen as one of China's best hopes to replace advanced graphics processor unit (GPU) chips sourced from US supplier Nvidia, was cut off by Taiwan Semiconductor Manufacturing Co (TSMC), according to a Bloomberg report. The move came after TSMC, which relies on core US technology for wafer fabrication, determined that making high-end chips for Biren could violate the US restrictions. Biren declined to comment on the report despite repeated requests.