CH559 主频配到48M时，UART0如何配置成9600波特，按照计算公式

x = 10 * FREQ_SYS / BUAD / 16;

x2 = x % 10;
x /= 10;
if ( x2 >= 5 ) x ++; 
最后的X值最大255，计算FREQ_SYS不能大于39.168M.

是没有办法吗？

of course there is a way....

for fSys = 48Mhz just use a reload Value of 0x64 and clear SMOD. 

difference is about 0.16%

check this out:

Replacement-WCHs-debug.c/doc at main · usbman01/Replacement-WCHs-debug.c (github.com)