28388D SCI_A received data is wrong

Hi, I have a problem in 28388D SCI communication.the code picture are as follow,the program is transmit the data what you received. on serial debugging interface. I can't receive what I transmit. So I went to CCS try to find out the reason. It turns out that whatever value the upper machine sends it receives value is 255. I don't why and where the bug is?

Thank for your help! Here are some screenshots

Answer 1

[yeyuan zhu]

The result of the problem was to set the oscillator to 10MHz in the hardware configuration