Single-Wire Interface

In this mode, communications to and from the ATECC608A-TFLXTLS take place over SDA, a single asynchronously timed wire, and the SCL pin is not used as part of the communications channel. Instead, the SCL pin may be enabled to function as a GPIO pin.

The overall communications structure is a hierarchical format:

Tokens

I/O Tokens implement a single data bit transmitted on the bus, or the wake-up event.

Flags

Flags consist of eight tokens (bits) that convey the direction and meaning of the next group of bits (if any) that may be transmitted.

Groups

Groups of data follow the command and transmit flags. They incorporate both a byte count and a checksum to ensure proper data transmission.

Packets

Packets of bytes form the core of the group (minus the byte count and CRC). They are either the input or output parameters of a CryptoAuthentication command or status information from the ATECC608A-TFLXTLS.

See the Microchip website for the appropriate application notes for more details on how to use any microprocessor to easily generate the signaling necessary to send these elements to the device, including C source code libraries. Also see Section Wiring Configuration for Single-Wire Interface for more information about how to connect the device in the Single-Wire Interface mode.