USB2/3 Compliance Testing in i.mx8QM

[YukioOyama]

Hi all,

We are developing a USB host device running Linux OS on iMX8QuadMax.

This device supports USB 2.0 High Speed and USB 3.0 SuperSpeed (it is a host device).

I want to test compliance tests to verify electrical characteristics. However, these tests require a test signal.

For USB2.0 Hi-speed

4 test modes are required for testing.

Does your Linux include EHSETT by default? 　If so, how is it called and used?

If your Linux does not include it, do you know of any source code similar to EHSETT?

I don't care if it's code by an outside open communitiy, please let me know.

For USB3.0 Super Speed

Does your i.mx8qm automatically transition to compliance mode?

If the transition were automatic, we would have nothing to do.

If it does not transition automatically, how do we generate CP0-7 signals? Please let me know the procedure.

Best Regards,

Yukio Oyama

[joanxie · Accepted solution]

1) can use memtool

2) refer to the register as below

Adjust USB3.0 to compliance mode registers--PORTSC1USB3（offset: 1_0490h）

/unit_tests/memtool 0x5b130490=0x0a000340

Name	PORTSC1USB3
Description	USB3 Port Status and Control
Bit #	31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16
Reset value	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Field definitions	WPR	DR	Reserved	Reserved	WOE	WOE	WOE	CAS	CEC	PLC	PRC	OCC	WRC	PEC	CSC	LWS
Bit #	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
Reset value	0	0	0	0	0	1	1	0	0	0	0	0	0	1	1	1
Field definitions	PIC		PortSpeed				PP	PLS				PR	OCA	Reserved	PED	CCS
Signal Names	Description
8-5 PLS	Port Link State (PLS), RWS. Default = RxDetect ('5'). This field is used to power manage the port and reflects its current link state. When the port is in the Enabled state, system software may set the link U state by writing this field. System software may also write this field to force a Disabled to Disconnected state transition of the port. Write Values: 0: The link shall transition to a U0 state from any of the U states. 3: The link shall transition to a U3 state from the U0 state. This action selectively suspends the device connected to this port. While the Port Link State = U3, the hub does not propagate downstream-directed traffic to this port, but the hub shall respond to resume signaling from the port. 5: If the port is in the Disabled state (PLS = Disabled, PP = '1'), then the link shall transition to a RxDetect state and the port shall transition to the Disconnected state, else ignored. 1-2,4,6-15: Ignored. State Encoding: 0: Link is in the U0 State, 1: Link is in the U1 State, 2: Link is in the U2 State, 3: Link is in the U3 State (Device Suspended), 4: Link is in the Disabled State, 5: Link is in the RxDetect State, 6: Link is in the Inactive State, 7: Link is in the Polling State, 8: Link is in the Recovery State, 9: Link is in the Hot Reset State, 10: Link is in the Compliance Mode State, 11: Link is in the Test Mode State, 12-14: Reserved, 15: Link is in the Resume State. Note: The Port Link State Write Strobe (LWS) shall also be set to '1' to write this field. This field is undefined if PP = '0'. Note: Transitions between different states are not reflected until the transition is complete. Refer to section 4.19 of xHCI specification for PLS transition conditions. Refer to sections 4.15.2 and 4.23.5 for more information on the use of this field

• PORTSC1USB3 field descriptions

[YukioOyama]

Hi joanxie-san,

Thanks for your reply.

You guided me through the register settings, doesn't that mean it automatically transitions to compliance mode?

Best Regards,

Yukio Oyama

[joanxie]

yes, I think so, you can use memtool to read this register to double check if bsp set to the compliance mode or not as default

[YukioOyama]

Hi joanxie -san,

Thanks for the quick reply.

I understood about the possibility of not transitioning automatically .

I can understand your suggestion to check the default behavior of the device to find out. However, I will take that test at an outside testing house. (because the measuring equipment to test it is very expensive and not available to us)

I will consider trying it pseudo.

It looks like I can make the transition to compliance mode with a 50 ohm termination and no response to LFPS.

I will open a new case if new questions arise. I'll close this case. Thanks.

Best Regards,

Yukio Oyama