The KCU1500 board implements a single I2C bus (IIC_MAIN_SCL/SDA_LS), wired through level-shifter U45 and then routed to a 1-to-8 channel I2C TI PCA9548 bus switch (U44). The bus switch can operate at speeds up to 400 kHz.
The KCU1500 board I2C bus topology is shown in This Figure.
User applications that communicate with devices on one of the downstream I2C buses must first set up a path to the desired target bus through the U44 bus switch at I2C address 0x74 (0b1110100). Table: I2C Bus Addresses lists the I2C address of the TCA9548 U44 bus switch target devices.