4.1 General Device Commands
The following table provides a summary of the general device commands:
| Command Name | Description | 
|---|---|
Counter | Increments and reads the monotonic counters | 
Info | Used to read revision and status information from the device | 
Lock | Used to lock the individual lockable slots in the device | 
Nonce | Used to generate or pass a number used once into the device | 
Random | Used to generate a 32-byte random number used by the system | 
Read | Used to read various zones of the device | 
SelfTest | Tests the various internal cryptographic computation elements | 
SHA | Computes a SHA-256 or HMAC digest for general purpose use by the system | 
UpdateExtra | Updates bytes 84 or 85 within the Configuration zone after the Configuration zone is locked | 
Write | Used to write 4 or 32 bytes to the device, with or without authentication and encryption | 
