TUSB8020B: Questions from Datasheet description.

Answers in-line below:

*1. When all register values are used with default values, are 2pin:SCL/SMBCLK, 3pin:SDA/SMBDAT, 22pin:SMBUSz/SS_DN2 "open"?

[JMMN] Yes, if not using SMBUS or I2C leave these pins open.

*2, After 8.5.1.11 Device Configuration Register 2 (offset = Ah), there is no Reset value on each Table.  Is the value listed in Figure xx. Resister Offset xh a Reset value?

[JMMN] Not every register will have a set value, the UUID and serial number are unique to each device.  In other registers the default value is shown in the Figure table and omitted in the bit descriptions.

*3. Register values listed in "Figure xx. Resister Offset xh" shows "X"  What does the X mean? For example, 1:0 bit in Figure 10. Register Offset 7h is X.

[JMMN] X means that the default register value may vary depending on the pin configuration.

*4. What does the X in 0Xh mean as the reset value in Table11?   Other Tables may have similar notation.

[JMMN] X means that the default register value may vary depending on the pin configuration.

*5. On "8.5.1.6 Device Configuration Register (offset = 5h) [reset = 1Xh]",  bit_5 enables/disables U1/U2.  What does U1/U2 mean?

[JMMN] U1/U2 are intermediate USB 3.x power states.

*6. On "8.5.1.8 Device Removable Configuration Register (offset = 7h) [reset = 0Xh]",  What determines whether a device can or cannot be removed?

[JMMN] This determines if a downstream port of a hub reports that its connected device is permanently connected or removable.

Regards,

JMMN