Setting Correct DDR Tool UART Output

[CSchutte]

I am working on a design that will be using the DDR Tool inside of the iMX8 Config to test the LPDDR4 connection to an iMX8MP. I see in the iMX8 Config tool and in section 4.1 of the DDR Tool User Guide that I should set the 'UART config' dropdown to the UART that is used for the A-core debug UART, and that I can use any of UART1-UART4.

By default in the iMX8MP, UART2 is the A53 debug output, but in my design I will need to mux UART2 away from the dedicated UART2_RXD and UART2_TXD pins and have it instead come from pins SAI3_TXFS and SAI3_TXC.

Can UART2 still be the main A53 debug output if it does not come from the dedicated UART2 pins? Will the DDR tool still work if my UART2 is set to come from the SAI3 pins I identify?

[JosephAtNXP]

Hi,

Thank you for your interest in NXP Semiconductor products,

You are correct, you can use the same UART instance with other PADs, you have to overwrite the registers for IOMUX in the .ds file.

3033_022Ch can set UART2_TX mux mode, change it for 3033_01C8h register write and adjust the value.

3033_048Ch set UART2_TX pad control, just reallocate the value to 3033_0428h.

The same for the UART2_RX.

All while keeping the debug index the same.

Regards