Abstract: JTAG test equipment arranged to establish an asynchronous data transmission connection with a JTAG-compatible device under test for the transmission of test data between test access ports (TAP) in the test equipment and device under test. The test data is synchronized at reception before the test access ports (TAP). The test equipment includes a computer program for adapting a test data sequence arriving in the format defined by the test access port for transmission on an asynchronous transmission path, and a transceiver (TR1) for adapting the test data sequence and transmitting it through the asynchronous data transmission connection to the device under test.

Abstract: JTAG test equipment arranged to establish an asynchronous data transmission connection with a JTAG-compatible device under test for the transmission of test data between test access ports (TAP) in the test equipment and device under test. The test data is synchronized at reception before the test access ports (TAP). The test equipment includes a computer program for adapting a test data sequence arriving in the format defined by the test access port for transmission on an asynchronous transmission path, and a transceiver (TR1) for adapting the test data sequence and transmitting it through the asynchronous data transmission connection to the device under test.

Abstract: A JTAG testing system including a JTAG test equipment and a device under test compatible with the JTAG configured to form a synchronous data transmission connection with one another for transferring test data through a transmission path placed between predetermined interfaces. An asynchronous connection can be used as the transmission path between the interfaces, whereby the test equipment and said device under test are provided with a transceiver on the transmission path side configured to arrange the test data to be sent from said interface into a mode appropriate for an asynchronous transmission path and correspondingly to arrange the test data to be received from the asynchronous transmission path into a synchronous mode required by said interface.