An apparatus comprises an implantable medical device that includes a storage circuit. The storage circuit includes a first stage circuit configured to receive an input signal and to invert and store information about a data bit received in the input signal, a second stage circuit coupled to the output of the first stage circuit to invert and store information about a data bit received from the first stage circuit, and an error circuit coupled to the output of the first stage circuit and an output of the second stage circuit. The error circuit generates an error indication when the storage circuit outputs match while the first stage circuit and the second stage circuit are in an inactive state.