The reference manual: http://www.wch-ic.com/downloads/CH32V003RM_PDF.html
Section 3.4 Register description (page 17 on v1.4) states
R32_RCC_CFGR0 has a reset value of 0x00000000.
This is incorrect. On a physical device, the reset value was found to be 0x00000020.
Please update the documentation or issue an errata for the CH32V003 part.
The reference manual: http://www.wch-ic.com/downloads/CH32V003RM_PDF.html
Section 3.4 Register description (page 17 on v1.4) states
R32_RCC_CFGR0 has a reset value of 0x00000000.
This is incorrect. On a physical device, the reset value was found to be 0x00000020.
Please update the documentation or issue an errata for the CH32V003 part.