TUSB321AI: DIR control not working properly, USB3 not working properly

I just checked that the board does NOT receive +5V when connected type-C to type-C

Hi Jakub,

Jakub Vanek said:

I just checked that the board does NOT receive +5V when connected type-C to type-C

What is not receiving 5V? VBUS or the CC pin? 

When there is a successful attachment, the voltage on the CC lines so should be within one of the ranges specified above, assuming there is a successful CC connection. 

Jakub Vanek said:

one type-c side:
CC1 => 5V
CC2 => +- 1.8V
DIR => 1.8V => ok

second type-c side:
CC1 => 0V
CC2 => 5V
DIR => 1.8V (should be log. 0?) 

I believe there should only be one CC pin pull-up, while the other is essentially 0V. There should be no point where both CC pins have voltage on them aside from a DRP configuration where UFP and DFP are toggling.

For the DIR pin on the TUSB321, I don't see any pull-ups on the pin, which is something we typically recommend:

Thanks,

Ryan

Hello Ryan, 

Thank you for your reply.

Ryan Kitto said:

What is not receiving 5V? VBUS or the CC pin? 

When we use type-c to type-c connection, the board does NOT receive VBUS power. 
When we use type-A to type-c connection (we are type-c), the power is fine. 

Ryan Kitto said:

When there is a successful attachment, the voltage on the CC lines so should be within one of the ranges specified above, assuming there is a successful CC connection. 

I believe we have VUFP_CC_HIGH because it was in this range; however, I could only measure it with a multimeter today, and it was somewhere between 1-1.8V (on the working USB3 side). I will measure it with an oscilloscope on Monday.

Ryan Kitto said:

I believe there should only be one CC pin pull-up, while the other is essentially 0V. There should be no point where both CC pins have voltage on them aside from a DRP configuration where UFP and DFP are toggling.

So the second type-C side is correct? Where on CC1 is 0V, and on CC2 is 5V? 

Ryan Kitto said:

For the DIR pin on the TUSB321, I don't see any pull-ups on the pin, which is something we typically recommend:

R46 is assembled on our board; however, is it really needed? The MUX hasan  internal pull-up on the SEL pin

Hi Jakub,

Jakub Vanek said:

When we use type-c to type-c connection, the board does NOT receive VBUS power. 

If the TUSB321 is not seeing VBUS, then it will not believe there is a connection made, as VBUS is used to detect an upstream connection, and is monitored by the VBUS_DET pin. If there is no VBUS, then the TUSB321 will likely fail to see a connection:

Jakub Vanek said:

So the second type-C side is correct? Where on CC1 is 0V, and on CC2 is 5V? 

Yes, this setup for the CC lines is more along what we would normally expect.

Jakub Vanek said:

R46 is assembled on our board; however, is it really needed? The MUX hasan  internal pull-up on the SEL pin

The DIR pin is an open drain pin, so it needs something pulling it up that will also allow the signal to go low if the DIR pin goes low. If the value of the pull-up in the mux does not affect the performance of the DIR pin, then it should be fine. 

Jakub Vanek said:

I believe we have VUFP_CC_HIGH because it was in this range; however, I could only measure it with a multimeter today, and it was somewhere between 1-1.8V (on the working USB3 side). I will measure it with an oscilloscope on Monday.

Yes, please double check this on a working CC connection.

Thanks,

Ryan