REG:TUSB2077 problem

rajarajan g

Other Parts Discussed in Thread: TUSB2077A

hi, I am using tusb2077a usb hub. while powered PORTDIS pin is low, HUBCFG is high, PORTPWR pin is high. for few seconds after that. external oscillator stops clocking and entering SUSPENDED MODE.suspend pin is high. sometimes it got detected as USB HUB while it is in suspended mode.

over 9 years ago

0 Elias Villegas M. over 9 years ago

TI__Guru* 76130 points

Hello,
What is the problem? The hub going to suspend is a normal behavior when there is nothing connected on the downstream ports.
Can you share your schematic?
The hub does not go by itself to suspend, the USB Host is the one that commands the hub to enter suspend. Can you take a scope capture of the power-up sequence?
Regards

0 rajarajan g over 9 years ago in reply to Elias Villegas M.

Prodigy 40 points

tusb.pdf

0 rajarajan g over 9 years ago in reply to rajarajan g

Prodigy 40 points

please find the attached schematic. while powered up
PORTDIS=1;
USBHUB=1;
PORTPWR=1;
SUSPND=0;

after few seconds or milli seconds.

all the above mentioned pins are low except SUSPEND=1; and i had connected a usb to serial converter using chip FT232RL didnt get power and not detected. but usb hub is detected on my pc as USB Hub.

0 rajarajan g over 9 years ago in reply to Elias Villegas M.

Prodigy 40 points

Interface

Interface forum

REG:TUSB2077 problem