The PCA9541 is a 2-to-1 I2C-bus master selector designed for high reliability dual master
I2C-bus applications where system operation is required, even when one master fails or
the controller card is removed for maintenance. The two masters (for example, primary
and back-up) are located on separate I2C-buses that connect to the same downstream
I2C-bus slave devices. I2C-bus commands are sent by either I2C-bus master and are used
to select one master at a time. Either master at any time can gain control of the slave
devices if the other master is disabled or removed from the system. The failed master is
isolated from the system and will not affect communication between the on-line master
and the slave devices on the downstream I2C-bus.
