AM6442: Ethernet interface and IOSET restriction on Pin multiplexing

Bhaskar Reddy

Intellectual 980 points

Part Number: AM6442

Tool/software:

In our AM6442 custom board, IOSET restriction on pin multiplexing was not followed for Ethernet interface

Present Pin allocation is as given below.

When compared with other eval boards our board connected differently

Is it possible to make this Ethernet pin allocation work ?

It slightly matches with IOSET1

over 1 year ago

+1 peaves over 1 year ago

TI__Guru 63155 points

The RGMII peripheral timing was not closed to support this combination of pin assignments. There is a very good chance this combination of pin assignments will introduce timing violations for the RGMII peripheral. This may not appear to be an issue when testing your system with a small sample size of AM64x devices that represents only a small range of process variation. The design needs to be corrected to ensure proper operation of the RGMII peripheral across process, voltage, and temperature.

Regards,
Paul

0 Bhaskar Reddy over 1 year ago in reply to peaves

Intellectual 980 points

Hi Paul,

Thanks for your reply.

We will be correcting the interface in next revision.

For now, Its good enough if we can make the present interface work to do basic testing on these prototypes. We will not look for performance.

Other than pinmux adjustments do you see any changes needed in dtb file or R5 example software to make this interface work?

0 peaves over 1 year ago in reply to Bhaskar Reddy

TI__Guru 63155 points

You can go ahead and use the peripheral for development if it appears to be working. Note: The peripheral may appear to be working as expected, but the port may experience reduced throughput. This can occur when timing is on the edge and the MAC is detecting CRC errors that require packets to be retransmitted.

I'm not familiar with software, so not able to answer your software questions. I suggest you create a new thread asking your software questions, so it gets assigned to appropriate software team.

Regards,
Paul

0 Kallikuppa Sreenivasa over 1 year ago in reply to peaves

TI__Guru**** 195519 points

Hello Bhaskar reddy,

Please include the below in the thread title to be assigned to a PRU expert.

changes needed in dtb file or R5 example software

Regards,

Sreenivasa

0 Bhaskar Reddy over 1 year ago in reply to Kallikuppa Sreenivasa

Intellectual 980 points

e2e.ti.com/.../am6442-software-changes-needed-in-dts-files-or-r5-examples-for-eth-cpsw-rgmii-interface-to-work-when-pinmux-is-not-as-per-ioset-recommendations

0 Kallikuppa Sreenivasa over 1 year ago in reply to Bhaskar Reddy

TI__Guru**** 195519 points

Hello Bhaskar Reddy,

the Thread will be assigned to the expert t support.

I will close this thread.

Regards,

Sreenivasa

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AM6442: Ethernet interface and IOSET restriction on Pin multiplexing