TIDA-00630: USB-C is not needed, what else can be left out from reference design?

Tommi Takkinen

Part Number: TIDA-00630
Other Parts Discussed in Thread: TUSB8041, HD3SS460, TPS65982, TPS65987D, TUSB1046A-DCI, TUSB1064, TUSB564

Hi all,

I have a customer-selected Qualcomm SOM with only one USB 3.1 superspeed interface. According to SOM datasheet it is possible to use USB for output as Displayport 4k@60Hz.

SOM also has pins DP_USBC_ORIEN and DP_AUX_EN_N outputs, EDP_AUX_P/N, and USB_CC1 and USB_CC2.

See attached picture of SOM USB3.1 Type-C with displayport reference design. That is the case when USB-C connector is in use.

Customer wants a design with this SOM, no USB-C connector, Displayport-connector (no miniDP that is in reference), some USB3 type-A ports and 5V external supply. All in same board, direct connection between SOM and IC's without cables/connectors.

I was looking for reference design TIDA-00630 that is the closest one of reference designs.

Components needed might be at least HD3SS460 MUX, Displayport-connector,TUSB8041 USB3-hub and USB3 type-A connectors.

Customer requires this design must be all-in-one standalone version, only 5V input supply and size as compact as possible.

Here comes the questions:

* what else can be left off from TIDA-00630 reference? How it can be simplified?

* Is that PD Controller TPS65982/-86/-87 etc. really necessary in this case without USB-C connector?

* there is no driver-ICs needed between HD3SS460 and DP-connector?

Any help is appreciated.

Attached picture may clarify what is needed:

Br. Tommi

over 3 years ago

0 Adam Mc Gaffin over 3 years ago

TI__Mastermind 30000 points

Hello,

The PD controller is only needed if they are implementing a USB Type-C port and wanting to support PD messaging. If they are not implementing this type of port, there is not need for them to implement a PD controller such as the TPS65987D

0 Tommi Takkinen over 3 years ago in reply to Adam Mc Gaffin

Prodigy 10 points

Hi,

USB-C is not needed.

Another question about HD3SS460:

Here is link to thread about HD3SS460, it sounds to me like USB3&DisplayPort together is only possible with 2k-resolution and all 4 lanes are needed for DP@4k meaning that USB3 is not then available. Can you confirm?

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/521777/how-configuring-tps65982-and-hd3ss460-in-docking-side-work-at-dp-4x-lanes

Is there any other IC's that are able to do USB3+DP with 4k at the same time?

Br. Tommi

0 Adam Mc Gaffin over 3 years ago in reply to Tommi Takkinen

TI__Mastermind 30000 points

Hi Tommi,

I have sent this question for the team responsible for the HD3SS460 who can better answer this. They will get back to you shortly.

0 David (ASIC) Liu over 3 years ago in reply to Adam Mc Gaffin

TI__Guru**** 179941 points

Hi Tommi,

You can use the TUSB1046A-DCI, which supports DP1.4 8.1Gbps. 2 lanes of 16.2Gbps is sufficient to support 4k@60Hz.

Thanks
David

0 Tommi Takkinen over 3 years ago in reply to David (ASIC) Liu

Prodigy 10 points

Hmm, this seems to be 2-inputs/1-output so it takes USB3 and DP as input and drives them to combined single output. I can't use that IC.

I have SOM that has USB-output and that needs to be outputted/splitted to USB3-port and Displayport 4k@60hz.

Br. Tommi

0 David (ASIC) Liu over 3 years ago in reply to Tommi Takkinen

TI__Guru**** 179941 points

Tommi

In that case, you would need the TUSB564 or the TUSB1064. The only difference between the TUSB564 and TUSB1064 is that the TUSB564 supports USB3.2 Gen 1 5G and the TUSB1064 supports USB 3.2 Gen 2 10G. Both devices can support DP1.4 8.1G.

Thanks
David

0 Tommi Takkinen over 3 years ago in reply to David (ASIC) Liu

Prodigy 10 points

Hi,

Things are going forward slowly but steadily.

Question arised when reading datasheets: should those TX and RX lines to be cross-connected like in UART-TX to UART-RX?

As can be seen in picture, D660 SOM is in top-left corner, its pin-names are from perspective of the SOM so TX means transmitter output pin of SOM.

According to TUSB1064 datasheet e.g. "pin 10, TX1n, Differential negative input for DisplayPort or differential negative output for USB3.1 upstream facing port". TUSB1064 should be configured to USB3+2-lane DP -mode. In DP-mode it is like TX-to-RX but in USB point-of-view it is TX-to-TX?

So which way these should be connected?

Br. Tommi

0 David (ASIC) Liu over 3 years ago in reply to Tommi Takkinen

TI__Guru**** 179941 points

Tommi

Do you have the 660SOM datasheet? I can only find the product brief on the Qualcomm website.

The TUSB1064 TX1/2 and RX1/2 are mapped in reference to the USB Type-C connector naming convention. For example, the TUSB1064 TX1 is connected to the Type-C TX1, etc.

Thanks
David

0 Tommi Takkinen over 3 years ago in reply to David (ASIC) Liu

Prodigy 10 points

Hi David,

Yes, I have SOM datasheet.

Br. Tommi

0 David (ASIC) Liu over 3 years ago in reply to Tommi Takkinen

TI__Guru**** 179941 points

Tommi

Can you please accept my friendship request and then you can send the me datasheet in a private message?

Thanks

David

0 Tommi Takkinen over 3 years ago in reply to David (ASIC) Liu

Prodigy 10 points

Hi,

Couple of clarifications still needed here:

In the picture, U5 (FSUSB43) is copy-pasted from SOM Hardware design guide where used with type-C connector. Is that really needed here?

"AUX_N/P must be disconnected in the system until the connection is switched into the
DisplayPort mode, per the USB Cable and Connector Specification. FSUSB43 isolates the
connection and switches the ports AUX_N and AUX_P on or off when needed. "

According to TUSB1064 datasheet this can be handled via register (AUX_SBU_OVR) by setting it either 00 or 11 and then there is no connection between SBU and AUX.

If U5 in not needed here:

-> how to route EDP_AUX_N (to SBU1) and EDP_AUX_P (to SBU2)?

-> are those 100k pull-up/down resistors R88/R89 still needed in these lines here?

-> how about 2M pull-downs R48/R49, are they needed?

EDP_AUX -lines are coming from dedicated pins of SOM. DP_AUX_EN_N and DP_USBC_ORIEN are coming from general IOs of SOM.

Br. Tommi

0 David (ASIC) Liu over 3 years ago in reply to Tommi Takkinen

TI__Guru**** 179941 points

Tommi

Since this is a non-Type-C design, I don't believe you need the FSUSB43 or the TUSB1064 SBU/AUX MUX. You can connect the AUX from the SOM straight to the DP connector.

The TUSB1064 SBU1/2 can be left open since we are not using them.

The TUSB1064 AUXP/N can be connected to the AUX bus between the SOM and the DP connector to snoop the AUX traffic for power management purpose.

The 2M is not needed since we do not use Type-C.

The 100k pullup/pulldown are still needed since this is a SOM requirement.

Thanks

David

0 Tommi Takkinen over 3 years ago in reply to Tommi Takkinen

Prodigy 10 points

Hi,

I have started layout work and noticed that these USB3_SS-lines are crossed in layout.

SOM is connected to TUSB1064 that outputs Displayport and it serves also USB3-HUB.

So question is: Are those lines in schematic connected correctly?

Br. Tommi

0 David (ASIC) Liu over 3 years ago in reply to Tommi Takkinen

TI__Guru**** 179941 points

Tommi

The connection looks to be correct. The D660 pinout was defined to be on the source side while the TUSB1064 pinout was defined to be on the sink side. Normally the cross is done in the USB-C cable, but now you will have to handle the cross in the PCB design.

Thanks

David

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TIDA-00630: USB-C is not needed, what else can be left out from reference design?