An electronic device having a functional portion and a test portion. The test portion includes a boundary scan register formed by a plurality of test cells arranged in the body according to a register sequence, where first test cells are configured to form a serial-to-parallel converter and second test cells are configured to form a parallel-to-serial converter. The test cells are each coupled to a respective data access pin of the device and to a respective input/output point of the functional part and have a first test input and a test output. The boundary scan register defines two test half-paths formed, respectively, by the first test cells and by the second test cells. The first test cells are directly coupled according to a first sub-sequence, and the second test cells are directly coupled according to a second sub-sequence.