MIMXRT1020-EVK board ENET PHY hardware initialization

[Rick_Bourgeois1]

On the MIMXRT1020-EVK board:

There is a 1k resistor pulling up the INTRP/NAND_Tree (R115) and another (R137) pulling it down.

I confirmed that these two resistors are stuffed on the board.

Pulled up means nand tree mode disabled, pulled down means nand tree mode enabled.

I don't know how the chip will respond to this situation.

GPIO_AD_B1_06 is connected to this pin and in example firmware it is an output and set to high before the ENET_RST is toggled.

My custom board floats this pin so should also disable nand tree mode.

My custom board ethernet faiils on the evkmimxrt1020_enet_txrx_transfer demo.

I pulled the pin up with a 1k resistor with no luck.

Autonegotiation fails.

I also float the RXD0/DUPLEX and the RXER/ISO.

The EVK board pulls down RXD0/DUPLEX for full duplex my board is half duplex.

I am struggling to debug this problem.

[Bio_TICFSL]

Hello,

You better follow up the Hardware Development Guide for the
MIMXRT1050/MIMXRT1060 Processor, is the same enet as 1020, if it has the pullup is for something and enet works as usual in this board.

Regards

[Rick_Bourgeois1 · Accepted solution]

There are 8 different boot configuration pins for the KZ8081.

I had 4 that mismatched the demo board but I thought I could configure them in software.

These mismatches were pins 16, 20, 30, 31 DUPLEX, ISO, NWAYEN, SPEED

I modified my prototype  and changed NWAYEN to DISABLE and SPEED to 10MBS with 1K PD.

It now works but i am questioning if I should also correct the DUPLEX and ISO.

Thanks, I am saying its solved with mysteries.