A microprogrammed control path architecture for an embedded IEEE 1149.1 test coprocessor

Abstract

This paper proposes a test coprocessor for a 32-bit MicroBlaze CPU core. A microprogrammed architecture is used to implement the coprocessor control path, offering a flexible solution that ensures a straightforward expansion of the test command set. The current version supports a set of SVF-like commands that is able to control one built-in IEEE 1149.1 boundary-scan infrastructure. The proposed test coprocessor is useful in a wide range of online test applications, and namely in the case of mission-critical embedded systems, where online fault detection and diagnosis become particularly important.