TUSB1210: Regarding the USB eye‑diagram test procedure

HI Vishesh 

Thank you for your reply. I would like to confirm the following points. Is the operation shown in the figure a protocol‑level operation for the USB Host Controller?

We are now using TUSB1210 instead of the original USB3320C_EZK. With the USB3320C_EZK, we were able to perform USB compliance testing. After switching to the TUSB1210, what modifications are required in the existing software in order to perform USB compliance testing?

Does the following operation flow comply with the process required in the diagram below?

1.Connect a USB analyzer or an oscilloscope to the port under test.

↓

2.The host sends the following USB command through the USB driver:
SET_FEATURE(PORT_TEST, wIndex high byte = 0x04)
→ Select Test_Packet mode
↓

3.After receiving the command, the Host Controller notifies the PHY (e.g., TUSB1210)
via the ULPI interface to enter the corresponding test mode.
↓

4.The PHY continuously outputs the test signal
(it will not stop until the device is powered off).
↓

5.Use an oscilloscope or compliance tester to capture the eye diagram or waveform,
and evaluate compliance according to the USB 2.0 specification.

If signal parameters need to be adjusted to pass the eye‑diagram test, is it necessary to configure the relevant TUSB1210 registers through the ULPI interface?

HI Vishesh 

Thank you for your reply. 

Regarding the statement “These parameters typically do not need to be adjusted for an eye diagram, but can be if needed,” if adjustment is required, could you please let us know which registers can be modified and how they should be adjusted?

Additionally, when performing compliance testing using the TUSB4041I, how should we select a specific downstream USB 2.0 port? Since the TUSB1210 has only one port, whereas the TUSB4041I has four downstream ports.

Thank you. 

HI Boris,

Boris liu said:

Regarding the statement “These parameters typically do not need to be adjusted for an eye diagram, but can be if needed,” if adjustment is required, could you please let us know which registers can be modified and how they should be adjusted?

I will check internally and get back to you on this.

Boris liu said:

Additionally, when performing compliance testing using the TUSB4041I, how should we select a specific downstream USB 2.0 port? Since the TUSB1210 has only one port, whereas the TUSB4041I has four downstream ports.

If you would like a full compliance report for the hub you will need to test all 4 ports individually. The performance of all 4 ports should be approx. equal, so passing compliance will be more of a test of layout implementation. 

HI Vishesh 

Thank you for your reply. 

Regarding the first question above, I will wait for your reply.

As for the second question, what I would like to ask is:
Are there any differences in software operations (entering test modes) during the compliance test between a standalone USB PHY and a USB hub?

Hello, 

We are OOO today for the U.S holiday. Expect a response by EOD tomorrow.

Thanks,

Ryan

Hi Boris,

The TUSB1210 is a single-port PHY, selecting the port to test is configured in the USB controller.  Using the TUSB1210 should be very similar to the USB3320C_EZK referenced above.

As far as compliance testing, a PHY is transparent to the test software used to place the Host/device in a compliance mode to send test patterns.  The compliance test software doesn't access the TUSB1210 but the USB Host/Device (the test procedure of a HUB is different than a Host, the USBIF has test tools and procedures for both).  

Vendor_Specific2 register (0x80) has additional controls for eye-diagram tuning(7.5.29 of the datasheet).  It's not recommended to adjust these settings unless necessary.

Regards,

Undrea

HI.Undrea

Thank you for your reply. 

Regarding HUB compliance testing: after entering test mode, all ports (e.g., 4 USB 2.0 ports) can undergo eye diagram testing without needing to switch ports individually. Is my understanding correct?

Regarding the earlier reply mentioning "the test procedure of a HUB is different than a Host, the USB-IF has test tools and procedures for both" — does "USB-IF" refer to the CPU? And are the test procedures and tools something I should consult with the CPU vendor for? For example, if I plan to use TI's AM625, should I contact the AM625 team to obtain the test tools and procedures?

Thank you.