Thank everyone for your attention. When Cy7c68013a is configured in GPIF mode for IN transfer, I find a error. for example, the data is 10,11,12,13,....,521,however, the data got in the host is 0,10,11,12,13,....,520. i.e, the first word is zero, and all the origin data shifted to the next place except the last of the origin which is lost. I have tested for times and the result is same. I don't known what's porblem. I thought it the inherent chip problem. Thank you again.