TUSB2046I: Problem of plugging after unplugging

Dice-K

Mastermind 6330 points

Part Number: TUSB2046I
Other Parts Discussed in Thread: TUSB4041I,

Hello.

If I plug the USB Device of Port-2 after unplugging it, the HOST of Port-1 is judged as low speed.

Is this behavior correct?

I want to use it at high speed mode.

Please let me know the simple countermeasure method.

Regards,
Dice-K

over 5 years ago

0 Malik Barton57 over 5 years ago

TI__Guru 64326 points

Dice-K,

TUSB2046I is a full speed hub not a high speed hub. TUSB4041I is a high speed hub which may be more suitable for your application.

0 Dice-K over 5 years ago in reply to Malik Barton57

Mastermind 6330 points

Hello Malik,
Thank you for your reply.

I'm sorry, my posting was a typo.

I want to use it at full speed mode.

Please let me know the simple countermeasure method.

Best regards,
Dice-K

0 Malik Barton57 over 5 years ago in reply to Dice-K

TI__Guru 64326 points

Dice-K,

In you figure is port 1 the upstream port of TUSB2046I?

0 Dice-K over 5 years ago in reply to Malik Barton57

Mastermind 6330 points

Hi Malik,
Thank you for your reply.

Yes, that's right.
The Port-1 is a upstream port.

Is this related to the problem?

Best regards,
Dice-K

0 Malik Barton57 over 5 years ago in reply to Dice-K

TI__Guru 64326 points

Dice-K,

The USB host on the upstream sets the "speed" of the bus according to the capabilities of the USB device in most cases. What USB device are you using? Is this device a full speed compatible device? There are many reasons this could be happening dealing with schematic and layout issues. Can you post the schematic and layout for this design?

0 Dice-K over 5 years ago in reply to Malik Barton57

Mastermind 6330 points

Hi Malik,
Thank you for your reply.

I post the schematic and layout for this design.

Please let me know problems.

Best regards,
Dice-K

0 Malik Barton57 over 5 years ago in reply to Dice-K

TI__Guru 64326 points

Dice-K,

What is the device you are using for this test? Also can you probe DP and DM to see if upon connection of downstream device DM or DP is pulled up?

0 Dice-K over 5 years ago in reply to Malik Barton57

Mastermind 6330 points

Hello Malik,
Thank you for your support.

> What is the device you are using for this test?
HOST : Renesas RX-seires Microcomputer
USB Device : It is not a memory but a device that mounts a microcomputer and communicates.
Since our company has not developed, we do not know the contents.

> Also can you probe DP and DM to see if upon connection of downstream device DM or DP is pulled up?
The DP of the downstream device is pulled up.

Best regards,
Dice-K

0 Malik Barton57 over 5 years ago in reply to Dice-K

TI__Guru 64326 points

Dice-K,

Just to confirm are you seeing the Host, the HUB, or the Device drop into low speed mode? Also how are you determining that it is dropping into low speed mode?

0 Dice-K over 5 years ago in reply to Malik Barton57

Mastermind 6330 points

Hi Malik,
Thank you for your reply many times.

My customer's information is as follows.

I do not know if it actually drops into low speed mode.

It judges by software.

By plugging in and out of the device connection side (DP1,DM1), it is confirmed that the PORT_LOW_SPEED bit is set for the status acquired by GetPortStatus on the Port-1 (DP0,DM0).

It is the question whether this is abnormal or not.

Best regards,
Dice-K

0 JMMN over 5 years ago in reply to Dice-K

TI__Guru 60865 points

Can you post the entire port status returned? The port_low_speed bit may be set due to an error or disconnect condition.

Regards,

JMMN

0 Dice-K over 5 years ago in reply to JMMN

Mastermind 6330 points

Hi JMMN,
Thank you for your support.

I attach the acquired log.

Best regards,
Dice-K

0 JMMN over 5 years ago in reply to Dice-K

TI__Guru 60865 points

Hi Dice-K,

The USB host is not changing from full speed to low speed. The port status that is changing is on Port 1 - the Ethernet gadget is connecting at full speed, then disconnecting and reconnecting at full speed. I don't see any device being connected at Port 2? Can you confirm what is being connected / disconnected in the log?

Thanks,
JMMN

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TUSB2046I: Problem of plugging after unplugging