5.1.8 SHA Command

The SHA command computes a SHA-256 or HMAC/SHA digest for general purpose use by the host system. The SHA computation is performed in a special section of internal ATECC608B-TNGTLS memory (Context Buffer) that is not read nor written by any other commands. Any arbitrary command can be interspersed between the various phases of the SHA command without problems. This SHA context is invalidated on power-up and wake. In most cases, if an error occurs during the execution of the SHA command, the context is retained without change.