A secure data transmission scheme for 1149.1 backplane test bus

The four (five) wires defined in IEEE Std 1149.1 can be extended to the backplane to form a test bus that provides a linkage between 1149.1 boards and the backplane environment. This test architecture has many advantages. However, one of the disadvantages is its inability to detect errors that may occur during backplane data transmission and to protect the boards-under-test from unsafe corrupted data. In this paper, we propose a novel scheme to address these issues. The concept is first described, then followed by implementation examples. As a result of its simplicity and flexibility, the proposed scheme can be implemented in different ways to suit specific application needs