i.MX 6 Solo Ethernet RMII interface

[vinayakammani]

Hi,

We have followed the hardware development guide to configure the RMII interface on i.MX6 Solo based board for the external clock reference. GPIO_16 is used to get the clock from external oscillator ( 50Mhz). Configured

GPR1[21] bit to zero to pick the external clock as a clock source.

Following are relevant configurations :

0x20E0214 = 0x12 ( also tried 0x02)

0x20E05E4 =  ((1<<12)|(1<<13)|(2<<14)|(2<<6)|(6<<3)|(1<<16))

0x20E080C = 0x00

0x20C406c =     Read(0x20C406c) |  3<<10

The question is apart from these configuration anything else missed to get Ethernet working with respect to clock configuration?  though we have valid TX descriptor data, don't seeing TX_EN line assertion for transmission. Apart from external clock config, any other system clock configuration dependency is there MAC to do transmit and receive. The clock source is reliable since we tested Ethernet working in U boot. facing this issue with nucleus environment. External clock is reference to transmit/receive/Management. the management interface with PHY is working as expected, only transmit/receive is failing.

Regards,

Vinayakam

[marcocavallini]

Check carefully you have SION bit activated

MX6QDL_PAD_GPIO_16__ENET_REF_CLK 0x4001b0a8 // enable SION

[vinayakammani]

Thanks for your comments.. I have already made SION enabled  ( 0x20E0214 = 0x12) for GPIO16. But still it is not working.

[marcocavallini]

What are you doing exactly?

[vinayakammani]

we are running a web server application on target, one can query the target IP details from the PC ( Web browser). Target is static IP configured. As part of init process ( IP attachment), there is a ARP request transmit out from the target. We actually measured the Signals out on MAC lines ( TX_EN, TXD0, TXD1, Clock), seeing no assertion on TX_Enable lines. Since clock is externally sourced, we could get clock running on the GPIO16. But not sure this clock been fed inside to MAC.  We configured the Ethernet controller and PHY as required. Appreciating to help us in identifying the issue area with your inputs.