Tool/software:
When the SMBus interface mode is enabled, the TUSB804x supports read block and write block protocols as a receiver-only SMBus device.
The TUSB804x will wait indefinitely for configuration by the SMBus host and will not connect on the upstream port until the SMBus host indicates configuration is complete by clearing the CFG_ACTIVE bit.
CFG_ACTIVE bit is on register 0xF8h.
Best
Brian