Zhaoxin is banned from using TSMC because they are dual-use. Which means they fall under the shared US/Taiwan export restrictions:
"additional license requirements for microprocessors having a processing speed of 5 GFLOPS or more and an arithmetic logic unit with an access width of 32 bit or more, including
those incorporating “information security” functionality, and associated “software” and “technology” for the “production” or “development” of such microprocessors."
TSMC only has this license for Nanjing/Fab 16.
"PLA procurement tenders require that systems support Zhaoxin chips, like the Strategic Support Force’s call for bids for a data management system on
behalf of PLA Unit 61081 that requires that the system support domestic chips like Feiteng, Longsun, Shenwei, or Zhaoxin."
2019: ordered all state offices to remove foreign hardware and software within three years
this was extended in 2022 to a by ~May 2024 date. Assume this will get its completion extended but will start with KX-7000/KH-50000 for x86 government desktops/servers.
If Zhaoxin wants its PLA/government contract they need to fabricate at SMSC/SMIC. Of which, VIA Next has SMIC labeled in foundries:
https://www.vianextech.com/competencies/
NDA over node used could be like a N+2 Enhanced/Plus/slight shrink or whatever. Since, I don't see why TSMC requires a NDA. Unless they know they are going to get in trouble for giving N6 to Nanjing.
The path of least resistance is the domestic variant with Zhaoxin uses SMIC and the global variant with VIA uses TSMC.
From VIA's 2022 annual report:
VIA TECHNOLOGIES, INC. owns 100% of VIA NEXT TECHNOLOGIES, INC.
"In addition to accelerating its momentum in China, VIA NEXT will continue to expand and develop new customer groups in other markets."
Taipei => Handles VIA's return to self-made chips instead of using Intel/Qualcomm/MediaTek/NXP. (Other markets)
Shanghai => Continues to support Zhaoxin. (China)