Jianlin Yu - Cupertino CA,
Santiago Fernandez-Gomez - Sunnyvale CA,
Samy Makar - Fremont CA,
Apple Inc. - Cupertino CA
An apparatus and method for protecting the contents of a secure register from scan accessibility is disclosed. The secure register may include a number of scannable elements within a scan chain. During a normal scan test mode, the scannable elements of the secure register may be accessibly, as data may be shifted to, from, or through these elements. During certain other modes (e. g. , a scan dump or memory dump), a bypass circuit may be invoked to effectively separate the scan elements associated with the secure register from the remainder of the scan chain. During operation in one of these modes, no data may be shifted to, from, or through the scan elements of the secure register. Accordingly, the bypass path may protect secure data stored in the secure register from unauthorized access.