scope:

ISO/IEC 11889 defines the Trusted Platform Module (TPM), a device that enables trust in computing platforms in general. ISO/IEC 11889 is broken into parts to make the role of each document clear. Any version of the standard requires all parts to be a complete standard.

A TPM designer MUST be aware that for a complete definition of all requirements necessary to build a TPM, the designer MUST use the appropriate platform specific specification to understand all of the TPM requirements.

Part 4 defines the commands that allow software to communicate with and use the TPM. It defines the command format as both the TPM and calling software must agree on the exact command format, as many of the commands require cryptographic authorization and the format of the authorization must be standardized.