3 Configuration Zone Updates

Table 3-1 lists the new fields added in the ATECC608B configuration zone. It also describes the differences between the two devices.

Table 3-1. Configuration Zone Updates
ByteATECC608BATECC508A
13AES_Enable – This byte enables/disables the AES functionalities for both AES and KDF commands.Reserved for future use.
18CountMatch – This byte enables/disables the CountMatch function and selects the slot to be used as the counter match key.OTP mode – Used to set Read-Only or Consumption mode to the OTP zone.
19

The Chip mode has been redefined. The new byte helps to reduce the power consumption of the device with three possible power modes. It also selects the source of the I2C address, either from the I2C_Address or the UserExtraAdd byte.

Chip mode
68UseLock – This new byte controls the transport lock functionality. It enables/disables the transport lock function and the slot to be used as the transport key.LastKeyUse (16 bytes) – This field controls the KeyID 15 limited-use functionality.
69VolatileKeyPermission – This new byte enables/disables the volatile key functionality and selects the volatile key slot for volatile key functionalities.
70-71

SecureBoot – This new byte configures the secure boot functionalities:

  • Selection of one of the Secure Boot modes.
  • Whether to set the Persistent Latch on a successfully Secure Boot command execution.
  • The slot to be used for digest/signature.
  • The slot to be used for public key.
  • The RNG to be used for the Secure Boot command.
72kdflvLoc – Index within the KDF (HKDF) input string, where the two bytes stored below (KdfIvStr) are located.
73

KdfIvStr – 2-byte KDF IV string that must be found in the KDF message for the KDF (HKDF) Special IV mode.

85UserExtraAdd – If nonzero, it is the I2C address this device will respond to on the bus.Selector byte – It selects which device will remain in Active mode after the execution of the Pause command.
90ChipOptions

The new byte provides the following features:

  • Whether to run the self-test automatically on power-on or wake-up.
  • Enables/disables the I/O protection key.
  • Enables/disables the KDF AES function.
  • Sets the ECDH and KDF protection functionality.
  • The slot to be used for the I/O protection key.
Reserved for future use.
96-127KeyConfig – In KeyType, two new types (AES, SHA) and the function to enable the key based on the state of the Persistent Latch were added.KeyConfig