Patent ID: 6988230

Claim:
An electronic device, comprising: a plurality of subdevices; a bypass multiplexer having a first input, a second input and an output; a test data input; a test data output coupled to the output of the bypass multiplexer; a plurality of test interfaces, comprising: a set of test interfaces, each test interface in the set of test interfaces being coupled to a subdevice from the plurality of subdevices, a test data out contact of a predecessor test interface in a chain of test interfaces being coupled to a test data in contact of a successor test interface in the chain; and a boundary scan compliant further test interface for controlling the bypass multiplexer, the further test interface having: a further test data in contact coupled to the test data input; and a further test data out contact coupled to the first input of the bypass multiplexer; wherein: a test data out contact of a last test interface in the chain of test interfaces is coupled to the second input of the bypass multiplexer; and the further test data out contact is further coupled to a test data in contact of a first test interface in the chain of test interfaces.