2.3.1 AC Parameters: Single-Wire Interface

Table 2-3. AC Parameters: Single-Wire InterfaceUnless otherwise specified, applicable from T_A = -40°C to +100°C, V_CC  = +2.0V to +5.5V, C_L = 100 pF.

Parameter	Symbol	Direction	Min.	Typ.	Max.	Unit	Conditions
Start Pulse Duration	tSTART	To Crypto Device	4.10	4.34	4.56	µs	—
		From Crypto Device	4.60	6	8.60	µs	—
Zero Transmission High Pulse	tZHI	To Crypto Device	4.10	4.34	4.56	µs	—
		From Crypto Device	4.60	6	8.60	µs	—
Zero Transmission Low Pulse	tZLO	To Crypto Device	4.10	4.34	4.56	µs	—
		From Crypto Device	4.60	6	8.60	µs	—
Bit Time(1)	tBIT	To Crypto Device	37	39	—	µs	If the bit time exceeds tTIMEOUT-SWI, ATECC608B may enter Sleep mode.
		From Crypto Device	41	54	78	µs	—
Turn Around Delay	tTURNAROUND	From Crypto Device	64	96	131	µs	ATECC608B will initiate the first low going transition after this time interval following the initial falling edge of the start pulse of the last bit of the transmit flag.
		To Crypto Device	93	—	—	µs	After ATECC608B transmits the last bit of a group, the system must wait this interval before sending the first bit of a flag. It is measured from the falling edge of the start pulse of the last bit transmitted by ATECC608B.
IO Timeout	tTIMEOUT-SWI	To Crypto Device	45	65	85	ms	ATECC608B may transition to the Sleep mode if the bus is inactive longer than this duration.

Note:

1. t_START, t_ZLO, t_ZHI and t_BIT are designed to be compatible with a standard UART running at 230.4 kBaud for both transmit and receive. The UART must be set to seven data bits, no parity and one Stop bit.