Q)how do I need to connect VBUS_US & VBUS_DS?
A) Connect the VBUS_US to VBUS of the host. VBUS_US is used to detect the connection from host. For normal operation VBUS_DS should be connected to local 5V supply.
Q)can I connect them to a local 5V DC-DC? can I leave them floating?
A) connect VBUS_DS to local 5V. don't leave it floating.
Q) I also doesn't need the OVRCURR& PWR_EN , can I leave theme floating?
A) OVRCURR pins should be pulled high and PWR_EN can be left floating.
The purpose of divider network on VBUS_US pin is to discharge VBUS faster in case of a disconnection event.
Please refer to the app note in teh link given below:
What is I2C address of the hub when configuring using external master? I couldn't find it on the datasheet nor the HX3 HW design guidelines.
When configuring the hub using the internal ROM, is it still possible to read registers from the I2C master (processor, FPGA etc.) during normal operation? or do I need to change the boot sequence to I2C master in order for the host to read registers during normal operation?
I2C slave address(7 bits) by default is 0x60. If you are enabling Pin strapping then the I2C slave address will depend on how you strap the I2C_DEV_ID pin. Refer to Table 6 on the HX3 datasheet.
It is not possible to read the HX3 registers by an external FPGA or processor in any of the boot modes. The USB hubs generally has an interrupt endpoint which the host will keep on polling to know thw status of the hub/downstream ports of the hub.
So I don't understand how can you read information like product&vendor ID from the hub. Where can I find application notes explaining this polling process?
Thank you in advance.
The host does this by GET_DEVICE_DESCRIPTOR requests to the hub. Refer to Chapter 10 of the USB 3.1 spec.
I'm designing currently a USB 3.0 Hub with this component CYUSB3304.
I have already purchased and tested the development board CY4609, and it's working well.
For my hub , i want to use the 5V DC of the UpStream for powered the usb component and 2 DownStream ports. So no need external 5V.
Do you have any recommendations for self powered the Hub?