ATSHA204_14 Datasheet, PDF (33/80 Pages) ATMEL Corporation – Atmel CryptoAuthentication

Table 7-3. AC Parameters — Single-Wire Interface
Applicable from T_A = −40°C to +85°C, V_CC = +2.0V to +5.5V, CL =100pF (unless otherwise noted).
Parameter Symbol
Direction
Min Typ Max Unit Notes
Start Pulse
Duration
t_START
To Crypto
4.10 4.34 4.56 μs
Authentication
From Crypto
4.60 6.00 8.60 μs
Authentication
Zero
Transmission t_ZHI
High Pulse
To Crypto
4.10 4.34 4.56 μs
Authentication
From Crypto
4.60 6.00 8.60 μs
Authentication
Zero
Transmission t_ZLO
Low Pulse
To Crypto
4.10 4.34 4.56 μs
Authentication
From Crypto
4.60 6.00 8.60 μs
Authentication
Bit Time⁽¹⁾
t_BIT
If the bit time exceeds t_TIMEOUT, then the
To Crypto
ATSHA204 may enter the sleep state. See
37 39 — μs
Authentication
Section 5.3.1, “I/O Timeout” for specific
details.
From Crypto
41 54 78 μs
Authentication
The ATSHA204 will initiate the first low-going
From Crypto
64 80 131 μs transition after this time interval following the
Authentication
Turnaround
start of the last bit (t_BIT) of the Transmit flag.
Delay
t_TURNAROUND
After the ATSHA204 transmits the last bit of
To Crypto
93
μs a block, the system must wait this interval
Authentication
before sending the first bit of a flag.
I/O Timeout t_TIMEOUT
The ATSHA204 may transition to the sleep
To Crypto
state if the bus is inactive longer than this
45 65 85 ms
Authentication
duration. See Section 5.3.1, “I/O Timeout”
for specific details.
Note: 1. t_START, t_ZLO, t_ZHI, and t_BIT are designed to be compatible with a standard UART running at 230.4Kbaud for
both transmit and receive. The UART should be set to seven data bits, no parity, and one stop bit.
ATSHA204 [DATASHEET] 33
Atmel-8740H-CryptoAuth-ATSHA204-Datasheet_072014