Abstract: An integrated circuit has a first scan cell segment, a second scan cell segment connected to one or more hidden content, and a scan cell circuit connected to the first scan cell segment and the second scan cell segment. The scan cell circuit alternatively provides access to the first scan cell segment and the second scan cell segment based on a state of the scan cell circuit.

Abstract: Various integrated circuits protect hidden content e.g., embedded instruments, keys, data, etc.) using scan cell circuit(s). For example, a first scan cell circuit is connected to the hidden content, and a second scan cell circuit is connected to the first scan cell circuit forming all or part of a serial data path. The first scan cell circuit provides access to the hidden content whenever the first scan cell circuit is in a first specified state and prevents access whenever the first scan cell circuit is in a different state. The first scan cell circuit does not interrupt the serial data path when the first scan cell circuit is in the different state. The second scan cell circuit changes an operational characteristic of the first scan cell circuit whenever the second scan cell circuit is in a second specified state. In some cases, the second scan cell circuit can be eliminated.

Abstract: An integrated circuit has a first scan cell segment, a second scan cell segment connected to one or more hidden content, and a scan cell circuit connected to the first scan cell segment and the second scan cell segment. The scan cell circuit alternatively provides access to the first scan cell segment and the second scan cell segment based on a state of the scan cell circuit.

Abstract: Various integrated circuits protect hidden content e.g., embedded instruments, keys, data, etc.) using scan cell circuit(s). For example, a first scan cell circuit is connected to the hidden content, and a second scan cell circuit is connected to the first scan cell circuit forming all or part of a serial data path. The first scan cell circuit provides access to the hidden content whenever the first scan cell circuit is in a first specified state and prevents access whenever the first scan cell circuit is in a different state. The first scan cell circuit does not interrupt the serial data path when the first scan cell circuit is in the different state. The second scan cell circuit changes an operational characteristic of the first scan cell circuit whenever the second scan cell circuit is in a second specified state. In some cases, the second scan cell circuit can be eliminated.