MCBSP的MCBSP_xrdy和MCBSP_rrdy问题

今天看到一个MCBSP的测试程序，

                   //Wait until the transmitter is ready for a sample, then write to it

                   while (!MCBSP_xrdy(hMcbsp));                      

                   MCBSP_write(hMcbsp,y);

                   //Wait until the value is received, then read it

                   while (!MCBSP_rrdy(hMcbsp));          

                   x = MCBSP_read(hMcbsp);

当MCBSP_xrdy(hMcbsp)为0时，表明数据正在写入DXR中，再将y写入hMcbsp，是否会产生冲突？

当MCBSP_rrdy(hMcbsp)为0时，表明DRR中的数据已经被读取，x = MCBSP_read(hMcbsp)语句如何理解？

整个MCBSP的收发过程是如何运行的，我理解反了？

谢谢，请高手指导指导。