DM3725: DM3725

Narendrababu S N

Part Number: DM3725

Hi All,

We have developed an end product with DM3725 chip set and TPS 65950 and USB functionality for local connectivity.

While USB certification,found that certification test case High speed upstream signal quality test is failing due to signal inversion but all associated data parameters in test are passing (data copied below).

Also, Inserting the Certification test report for your reference.

See page number 13-15 of attached document for more details on High Speed Upstream Signal Quality.

TUV SUD_IsatPhone 2 w_Fail_Test Report_20171215.pdf

over 6 years ago

0 Narendrababu S N over 6 years ago

Prodigy 50 points

Schematics details :

We double checked the HW schematic and traced D- to T11 (USB negative) and D+ to T10 (USB positive) from connector to processor. So from HW point D- and D+ are not crossed.

0 Cvetolin Shulev-XID over 6 years ago in reply to Narendrababu S N

TI__Guru 65405 points

Hi Narendrababu,

The USB signal inversion issue seem not hardware related but I suspect incorrect configuration. See AM/DM37x Multimedia Device Technical Reference Manual (Silicon Revision 1.x) section 22.2.2.4 Serial Interfaces - Caution:
It is possible to change the polarity of the TXEN signal for each USB port using the following bits:
• CONTROL. CONTROL_WKUP_CTRL[2]M_FSUSB3_TXEN_N_OUT_POLARITY_CTRL
• CONTROL.CONTROL_WKUP_CTRL[1]MM_FSUSB3_TXEN_N_OUT_POLARITY_CTRL
• CONTROL. CONTROL_WKUP_CTRL[0]M_FSUSB3_TXEN_N_OUT_POLARITY_CTRL

www.ti.com/.../technicaldocuments

BR
Tsvetolin Shulev

0 Narendrababu S N over 6 years ago in reply to Cvetolin Shulev-XID

Prodigy 50 points

Hi Tsvetolin Shulev,

Thanks for your quick response.

It seems that TXEN signal setting are applicable when we configure our device in Host mode but our device is configured for peripheral mode.
Could you confirm still your suggestions (given in above comment ) holds good for DUT in peripheral mode.

BR,
Narendrababu

0 Narendrababu S N over 6 years ago in reply to Narendrababu S N

Prodigy 50 points

Hi There,

Any further updates on this issue. Waiting for your response.

Thanks,

BR,

Narendrababu S N

0 Cvetolin Shulev-XID over 6 years ago in reply to Narendrababu S N

TI__Guru 65405 points

As you are using a custom board it should be helpful to perform your test on DM37xx EVM board with the same configuration to compare the results.

BR
Tsvetolin Shulev

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DM3725: DM3725