SERIAL DATA TRANSFER SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a serial data transfer system which can automatically check the transfer of data via an ASIC with no use of a CPU and also with the signal direction kept as it is, can automatically detect the rate of data and also can improve the transfer reliability of serial data after a test mode is canceled. SOLUTION: A processing circuit provided at the test data transmitting side transmits the logics of a start bit and a 1st bit of test data after inverting them. A processing circuit provided at the test data receiving side includes a 1st edge detection means which detects the start edge of a start bit of test data and a 2nd gate detection means which detects the end edge of the start bit. A start bit length time measuring means 12a detects the start bit length via the 1st and 2nd edge detection means.