TPS65981: Pulse outputs for CC1 and CC2 have suddenly dissappeared !!

Thanks for the response Eric !

I do have firmware loaded (successfully).

I will check that register .....

Bill

Hi Eric !

We validated that the firmware IS being loaded (by checking the register).

I believe my firmware engineer has that EVM ... but again, this is our second rev of the board.  The Alpha boards work fine.  These boards DID work fine for a week, now 8/9 boards do not have the CC outputs.  I've isolated those signals from the circuit and there is no pulsing.  One CC does go high, the other low ...

There is no other register or input that can control these two lines ?

Bill

It’s actually a little strange to me that the CC lines are toggling. If you look at the setting in the configuration utility, it says “Presents R_d on CC, supports data/power role swap”. That should mean that both CC lines are tied to ground through R_d when there is no connection.
Did you think we’ve got it in one of the configurations that says “Toggles R_p/R_d on CC”, which is typical of a DRP.

Here is a dump of our system config register :
It matches what the configuration utility says it should be:

0x80808080 0x28 0 18 0x1414000006059d80dc2a150ee9153f030a

It appears that it is 18 bytes long, and not 17 like it says in the documentation.
There are other discrepancies as well.
Is there updated documentation ?

Thanks

Bill

Now THAT is really strange !! The GOOD board (all is working just fine) is the 1 out of 9 boards that is toggling CC1,CC2 (with no cable in) ?!? The other boards have no toggling. They are all configured identically.

Hi Eric .... I have some more info on this problem and thought maybe you could comment.

Again, out of 9 boards 1 is still working.

I THINK it's because of he 8 bad boards, they were all used to charge a phone, via USB C, in High charge mode (9V) using the TPS65981.

I tracked down the failure today to the CC1, line on the TPS65981, being stuck HIGH when the device is powered.

This invalidates an output I am using to drive a direction mux on our (Microchip) hub which then sets the wrong USB 3.0 high speed TX/RX) bus.

So ... what might make the CC1 output from the TPS65981 remain high (when powered) ?

Thanks

Bill

OK. Understood. So the device should NEVER (if not damaged) pull CC1 high, but not CC2 ??

oops.. I should have specified. I have NOTHING connected and the PD is pulling CC1 (only, not CC2) HIGH ! Again, we are not configured as a DRP.

Hey Eric ... I had the TPS65981 replaced ... and have the same result !!  Namely, CC1 is being pulled high (CC2 low) by the TPS.

I'm running low on options.

Can  send you the config file and have you take a look ?

I tried to attach, but it complained about h file type.

I have already reflashed it several times.  It seems to be programming fine.

Bill

 

Eric .. here is the PJT.

Update ... we found the BIG problem (a damaged switch on the CC lines.

But, we still have the CC lines toggling out of the PD controller (and everything works fine).

My firmware guys suspects a bug in your config tool.  He will be trying our config on your eval board ...5633.pi_beta_1_1.pjt

Hi Bill,

If the CC lines are still toggling out of the PD controller, I don't think that is an issue with the TPS65981. What do you mean there is a damaged switch on the CC lines?
Also, what bug do you think was found with the config tool?

Thank you,
Eric

Exactly ! But they are (I promise:) That is what we think is the bug.

We are switching the CC lines to support a secondary host. The switch went bad (overvoltage). That was our main problem (not a damaged TPS65981, which I replaced). It has been fixed. However, with our config, the CC lines are still toggling out of the PD. Trust me :)