topic Re: Loopback modes with TJA1100 Issue in MPC5xxx

Loopback modes with TJA1100 Issue

ahmedsaber — Mon, 17 Feb 2020 21:19:31 GMT

Hello All,

In an Automotive project we are using TJA1100 as a PHY, I'm trying to validate the functionality of the 100BASE-T1 PCS and PMA functions.

So according to the TJA1100's datasheet in the loopback section,

I followed the steps to put the PHY in the external loopback mode as mentioned in the application notes AN12088

But when I put the PHY in the external loopback I sent the data successfully but I didn't receive anything

To validate the loopback at all I tried the internal loopback mode, it works fine as Tx and Rx but also there was an issue which is the data transmitted on the bus, while it must not

Any answer please

Thanks

Ahmed Saber

Re: Loopback modes with TJA1100 Issue

Bulat — Tue, 18 Feb 2020 11:43:42 GMT

Can you describe how you run external loopback test step by step?
What is TRX pins connection during the test?

Regards,

Bulat

Re: Loopback modes with TJA1100 Issue

misonyo — Fri, 25 Sep 2020 07:15:48 GMT

hello ，can you tell me what's the problem you meet? how to solve this problem??

i meet the same problem like you.

Re: Loopback modes with TJA1100 Issue

misonyo — Sun, 27 Sep 2020 06:52:02 GMT

hello，should I connect TRX PINS to other PHYs? I meet the same problem when i use TJA1101.

Re: Loopback modes with TJA1100 Issue

thosewhowish2b — Mon, 12 Jul 2021 10:10:14 GMT

Hello Ahmed,

did you have any luck on this?

By the way, how did you manage to do even the internal loopback? So far I have had no success with that.

Best regards.