IMX6DL rev 2.0 uart problem

I.MX6
1

Dear all

I have a unknow behaviour on som imx6 dual lite rev 2.0 SRMX6DLW00D01GE008V20A0 related to the uart1_tx_data port.

On my project that uart is connected to a gps for communication at 3.3V.

The problem is that the low level do not stay at 0V but remain at 0.9V.

The line is directly connected with only a 51ohm series to limit the emission due to the transitions.

Using same som but rev 1.5, the problem is not present and the uart low level stay at 0V allowing communications with the gps.

Any suggest that explain and help to solve this issue?

Thank you in advance

2

Is this your own custom carrier? If it is ours, what variant of the carrier are you using? Thanks