Arbitration using SDA Every controller monitors the bus for start and stop bits and does not start a message while another controller is keeping the bus busy. However, two controllers may start transmission at about the same time; in this case, arbitration occurs. Target transmit mode can also be arbitrated, when a controller addresses multiple targets, but this is less common. In contrast to protocols (such as Ethernet) that use random back-off delays before issuing a retry, I2C has a deterministic arbitration policy. Each transmitter checks the level of the data line (SDA) and compares it with the levels it expects; if they do not match, that transmitter has lost arbitration and drops out of this protocol interaction.
arbitration using sda every controller monitors the bus for start and stop bits and does not start a message while another controller is keeping the bus busy however two controllers may start transmission at about the same time; in this case arbitration occurs target transmit mode can also be arbitrated when a controller addresses multiple targets but this is less common in contrast to protocols (such as ethernet) that use random back-off delays before issuing a retry i2c has a deterministic arbitration policy each transmitter checks the level of the data line (sda) and compares it with the levels it expects; if they do not match that transmitter has lost arbitration and drops out of this protocol interaction