Patent ID: 7620866
Filing Date: 2009-11-17
Classification: G01R

Abstract:
1. A test access architecture for testing a cascade of modules embedded in an electronic circuit, each of the modules being isolated from surrounding circuitry by an associated test wrapper that provides switching functionality between functional access and test access to the module associated with the test wrapper, the test access architecture comprising: a test access mechanism arranged to transport test stimulus data to a module of the cascade that is in a test mode and to transport test response data from the module in the test mode, the test access mechanism configured to transport the test stimulus data and the test response data via a single data path that passes through each module of the cascade; circuitry configured to provide a global enable signal to each of the modules, the global enable signal provided for placing the modules in the test mode; and a plurality of control circuits, each of the control circuits associated with one of the modules and each of the control circuits arranged to control whether the global enable signal is passed to the module associated with the control circuit.