Colibri iMX6ULL 256MB Rev 1.1A
Linux 5.6.0+build.18
Custom carrier board
Hello,
We have a product that uses a Colibri VF50 module on a custom carrier board. There is a fairly large number of products in the field over a number of years. We have experienced no Ethernet issues with the product whatsoever.
We have recently investigated replacing the VF50 module with an IMX6ULL module using the same carrier board. However, we cannot get the IMX6ULL Ethernet to work with our carrier board. The carrier board Ethernet circuit appears exactly the same as described in the “Colibri Carrier Board Design Guide”.
For test, I have installed both IMX6ULL Linux LTS 3.0.4 and 5.6.0+build.18, both exhibit the same behavior.
On boot, the log shows:
[ 1.730287] libphy: fec_enet_mii_bus: probed
[ 1.748658] fec 20b4000.ethernet eth0: registered PHC device 0
[ 18.370966] fec 20b4000.ethernet eth0: Unable to connect to phy
The carrier board Ethernet connector Link and Link Activity LED’s flash on and off repeatedly.
A schematic of the Ethernet circuit is provided.
FB5 is WURTH ELEKTRONIK 742792641
The issue seems very similar to this one:
The IMX6ULL module Ethernet port appears to work fine in the Iris Rev 1.1 carrier board.
Any help will be most appreciated.
