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TUSB2077A: TUSB2077A only recognized as USB1.1 hub

Part Number: TUSB2077A

Hi all,

I have a new design with the TUSB2077A as a hub for several USB devices on my PCB. When I connect the TUSB2077A to the Host PC, and run a USB debug software like "USB Device Tree Viewer", the TUSB2077A is only displayed as a USB1.1 hub. Also when I copy files from the PCs SSD to a USB stick, I get only about 1MByte/s. Which correlates good with the USB1.1 enumeration.

I tested the USB stick also directly on the PC and it writes with more than 30MByte/s, so thats not the problem.

Initially I forgot the pullup on the DP0/DM0 and put it on the PCB afterwards between DP0 and DP0PUR. But the hub is still enumerated as USB1.1. Changing the Pullup to DM0, the USB hub is still a USB1.1 (as intended).

Any ideas, why the USB hub is only recognized as a USB1.1 hub and not a full-speed device?

This is the output of USB Device Tree Viewer:

      ========================== USB Hub =========================

        ------------------- USB Hub Descriptor -----------------
bDescriptorLength        : 0x09 (9 bytes)
bDescriptorType          : 0x29 (Hub Descriptor)
bNumberOfPorts           : 0x07 (7 Ports)
wHubCharacteristics      : 0x0009
 Power switching         : Individual
 Compound device         : No
 Over-current protection : Individual
 TT Think Time           : At most 8 FS bit times
 Port Indicators         : Not supported
bPowerOnToPowerGood      : 0x32 (100 ms)
bHubControlCurrent       : 0x64 (100 mA)
DeviceRemovable          : 0x00
 Bit 0                   : 0 (reserved, any value)
 Bit 1                   : 0 (Device at Port 1 is removable)
 Bit 2                   : 0 (Device at Port 2 is removable)
 Bit 3                   : 0 (Device at Port 3 is removable)
 Bit 4                   : 0 (Device at Port 4 is removable)
 Bit 5                   : 0 (Device at Port 5 is removable)
 Bit 6                   : 0 (Device at Port 6 is removable)
 Bit 7                   : 0 (Device at Port 7 is removable)
PowerControlMask         : 0xFE
Data (HexDump)           : 09 29 07 09 00 32 64 00 FE                        .)...2d..
HubIsBusPowered          : 0x00 (Self Powered)

        -------------- Extended USB Hub Descriptor -------------
HubType                  : USB 2.0 Hub
HighestPortNumber        : 7

        ------------------- USB Hub Descriptor -----------------
bDescriptorLength        : 0x09 (9 bytes)
bDescriptorType          : 0x29 (Hub Descriptor)
bNumberOfPorts           : 0x07 (7 Ports)
wHubCharacteristics      : 0x0009
 Power switching         : Individual
 Compound device         : No
 Over-current protection : Individual
 TT Think Time           : At most 8 FS bit times
 Port Indicators         : Not supported
bPowerOnToPowerGood      : 0x32 (100 ms)
bHubControlCurrent       : 0x64 (100 mA)
DeviceRemovable          : 0x00
 Bit 0                   : 0 (reserved, any value)
 Bit 1                   : 0 (Device at Port 1 is removable)
 Bit 2                   : 0 (Device at Port 2 is removable)
 Bit 3                   : 0 (Device at Port 3 is removable)
 Bit 4                   : 0 (Device at Port 4 is removable)
 Bit 5                   : 0 (Device at Port 5 is removable)
 Bit 6                   : 0 (Device at Port 6 is removable)
 Bit 7                   : 0 (Device at Port 7 is removable)
PowerControlMask         : 0xFE
Data (HexDump)           : 09 29 07 09 00 32 64 00 FE                        .)...2d..

        ----------------- USB Hub Capabilities ----------------
HighSpeedCapable         : No
HighSpeed                : No
MultiTtCapable           : No
HubIsMultiTt             : No
ArmedWakeOnConnect       : No
IsBusPowered             : No
IsRoot                   : No
Data (HexDump)           : 00 00 00 00                                       ....