Hi, LiPing,
Sorry for the delay. Regarding your question, I suppose that you want to reinitialize the SPI receiving shift register, as you know the SPI receiving shift register is invisible by7 software. In the case, I suggest you clear the CPHA bit, the SPI receiving shift register will be initialized after the falling edge of chip select signal /SS with the CPHA bit cleared.
Hope it can help you.
BR
Xiangjun Rong