5.2.1 Word Address Values

During an I²C write packet, the ECC608-TNGHNT interprets the second byte sent as the word address, which indicates the packet function as it is described in the table below:

Table 5-2. 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 ECC608-TNGHNT 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 ECC608-TNGHNT 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.