3.14.1 Protocol

MTCH2120’s registers can be accessed using 16-bit addressing.

START (S)

After a bus Idle state, a high-to-low transition of the SDAx line while the clock (SCLx) is high determines a Start condition. A Start condition must precede all data transfers.

DEVICE-ADDRESS

Initiate communication by transmitting the 7-bit device address along the start signal to select the client device. Upon successful selection, the client device will acknowledge by sending an acknowledgment bit to the host, indicating its readiness to receive a command.

MEMORY ADDRESS

This 16-bit selection determines which address the host wanted to read/write data from/to the device.

DATA

The state of the SDAx line represents valid data when, after a Start condition, the SDAx line is stable for the duration of the high period of the clock signal. There is one bit of data per SCLx clock.

ACKNOWLEDGE (A) OR NOT ACKNOWLEDGE (N)

All data byte transmissions must be Acknowledged (ACK) or Not Acknowledged (NACK) by the receiver. The receiver will pull the SDAx line low for an ACK or release the SDAx line for a NACK. The Acknowledge is a one-bit period using one SCLx clock.

STOP DATA TRANSFER (P)

A low-to-high transition of the SDAx line while the clock (SCLx) is high determines a Stop condition. All data transfers must end with a Stop condition.