Other Parts Discussed in Thread: TIDA-00882, , TPS65982
Hi,
After taking a look at the TIDA-00882 several questions on the TUSB9261 have come up:
1) Reference Design's I2C Interface: GPIO0, GPIO6, and GPIO1 are being used as an I2C interface between the TUSB9261 and the PMIC, TPS65982. Looks like the TUSB9261 is the bus master. We are not using this interface. I am assuming that we do not need to use this interface, and the TUSB9261 will work fine without any other device hanging off of it. Regardless, do we need to add pullups to GPIO0 (SDA), GPIO6 (IRQ1Z) , and GPIO1 (SCL)? Right now we have these pins unconnected and floating.
2) Reference Design's GPIO4, JACK_DETECT: I have seen some other documentation for this pin. It appears it is configured as an input pin to tell the TUSB9261 that it is being supplied by an External Supply, and not from the USB Cable. What is the proper use of this pin? How does the TUSB9261 operate differently on External or USB cable power? We have left the pin floating. I am assuming we should pull it high or low. Any advice?
3) Reference Design's GPIO10, SATA_EN: This is an output pin to control the power to the SATA HDD device. On our board, I never see this pin move. It is always high. We have a pull-up on this pin, so I don't know if it is being driven or floated by the TUSB9261. Does the Firmware really do anything with this pin?
4) Reference Design's GPIO11, FAULT#: This is configured as an input pin that is driven low when SATA HDD device (and TUSB9261) is exceeds a current limit setting. We have left this pin floating. Is this ok, or should we add a pull-up?
5) Regarding remaining GPIO Pins, GPIO2, GPIO3, GPIO5, and GPIO7. On the reference design, they all are effectively left unconnected/floating. Even though at least one of them, GPIO5 appears to configured as an input. Is it ok to leave them all of them floating, or should we add some pull-ups or pull-downs?
6) Regarding the USB interfaces. We are only using the USB 2.0 interface. We are not using the USB 3.0 connections. I just want to confirm that it is ok to leave the 4 USB.3.0 pins floating.
