Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Holtek/HT32F275x/USART0/USART0_MODSR#0x0
USART0_MODSR
DCTS
DDSR
DRI
DDCD
CTSS
DSRS
RIS
DCDS
Reserved.
https://github.com/cmsis-svd/cmsis-svd-data