7.2.1 Word Address Values

During an I2C write packet, the ATECC608B-TNGTLS interprets the second byte sent as the word address, which indicates the packet function as it is described in the table below:

Table 7-2. Word Address Values
Name Value Description
Reset 0x00 Resets the address counter. The next I2C read or write transaction will start with the beginning of the I/O buffer.
Sleep 
(Low-power) 0x01 The ATECC608B-TNGTLS goes into the low-power Sleep mode and ignores all subsequent I/O transitions until the next Wake flag. The entire volatile state of the device is reset.
Idle 0x02 The ATECC608B-TNGTLS goes into Idle mode and ignores all subsequent I/O transitions until the next Wake flag. The contents of TempKey, MessageDigestBuffer and Alternate Key registers are retained.
Command 0x03 Writes subsequent bytes to sequential addresses in the input command buffer that follow previous writes. This is the normal operation.
Reserved 0x04 – 0xFF These addresses must not be sent to the device.