3.1.1 Modifiable Configuration Zone Bytes

No bytes within the Configuration Zone can be directly written because the Config Zone is already locked. Several bytes can still be modified through the use of other commands.

SlotLocked Bits

For the ECC608-TNGHNT, the following individual slots have been configured to be slot lockable: Slots 0, 3-4, 6 and 8. These can be locked through the SlotLock mode of the Lock command. Each slot where this feature is enabled can be individually locked just once. Once a slot has been locked, it can never be modified or unlocked but can still be used based on the Access Policies defined for that slot.

Bytes 88 and 89 store the SlotLocked bytes. Initially, all bits in these bytes are set to a value of one. For those slots that have been locked, the value of the respective bit will be set to a value of zero.

I2C Address Redefinition

This device configuration has been created such that the I2C address can be redefined one time. The UpdateExtra command can be used to rewrite byte 85 of the Configuration zone to a new I2C address. When this byte is set to a non-zero value, the device configuration uses byte 85 as its I2C address instead of the default address. Once this byte has been rewritten, the device must be powered-down or put into Sleep mode before this change takes effect.
Important: If there is no need to change the I2C address, this location must be written with the default I2C address.

User Extra Byte

The UserExtra byte can be used for any desired purpose. This byte can be updated just once with the UpdateExtra command. The UserExtra byte is located at byte 84 of the Configuration zone.

Counter[0,1]

While the counters are not used by this device, they are not disabled. If so desired, the monotonic counters may be used by the system. Note that the counters are initialized to zero and can count to the maximum value of 2,097,151. The counter value can be incremented or read through the use of the Counter command. How this counter is used is strictly up to the system and independent of anything else on the device. Counter values can be read or updated using the Counter command.