Add DCDC function to the bottom board of B01 development board as needed. After welding, it is found that USB has no power output. After inspection, the enable end of the USB power supply chip TPS259530 is controlled by the RTS5411 chip self-powered control pin (DSP1_PWR). The RTS5411 manual describes that the self-powered control pin (DSP1_PWR) is active low and the USB power chip enable pin is active high. DSP1_PWR outputs high level after the B01 development board purchased from the official website is powered on. I would like to ask what is the cause of this phenomenon
Are you talking about nano, not TX2, right? DSP1_PWR initial output is custom setting in efuse.
The USB hub has an eFuse (one time programmable). If you are using the same USB hub from Realtek you need to contact Realtek for an excel spreadsheet where you can outline the functionality that you desire. Then Realtek can provide a firmware to you that they can flash. In that case you must have an external SPI flash that you can program or you can work with Realtek to figure out how to OTP the part and not stuff an external SPI flash.
If you do not want to flash any firmware, then the HUB comes with default settings. Which again you can ask Realtek for the spreadsheet that outlines the default behavior. That way you can design around the default settings. In this case, the default behavior for the DSP enable pins is active low unless otherwise programmed to be different.