TM4c129xnczad - No auto-negotiation and no link

Hello,

i didn´t get the Ethernet(internal PHY) on my self-designed board with an TM4c129xnczad processor working.

Here are the Register values of my internal PHY:

BMSR: 0x7849 (no link and no negotiation)

The Board is connected to my Windows 7 PC but the auto-negotation will never be finished and also couldn´t the PHY establish a link.

Here are some values I measured on the PHY:

TX_CLK: 25Mhz

TX_EN: HIGH when transmitting on TXD_0/1/2

X1: 25Mhz

X2: not connected

25MHZ_OUT: 25Mhz

RESET_N: HIGH (low active)

3.3V supply: 3.3V

PFB(IN/OUT): 1.8V

Resistance RBIAS to ground: 4.87 kOhm (from circuit layout)

Resistance TD/RD to termination: 50 Ohm (from circuit layout)

I also tried it with a fixed 100Mbit/FullDuplex and 10Mbit/FullDuplex configuration but there also couldn´t be a link established.

But if i try the same code with the Tiva C series ARM MCU Development kit provided by TI with processor TM4C129xnczad. I am able to do communication and getting 

BMCR = 0x786D (Auto negotiation completed and link is up)

 

I also looked at my hardware and checked following things :

1. Power up the board and verified key voltages

1. Probe the RBIAS pin 
   1. The voltage should be ~1.2V. The RBIAS pin sets the main reference bias for the device.  If the voltage or current for this pin is not correct, it could affect the entire device. 

2. Power down the board and verified key resistances

1. Resistance to ground across the RBIAS resistor should be 4.87 kOhms +/- 1%.
2. Resistance across the transmit and receive terminations should be 50 Ohms +/- 1%.

3. Before Ethernet Initialization the Flash Prefetch must be turned OFF by writing 1 to FLASHCONF.FPFOFF. After completing Ethernet Initialization, the user code must turn ON the Flash Prefetch by clearing the FLASHCONF.FPFOFF bit to restore system performance

 

Even after verifying above all points i cannot see the link is established and AUTONEGOTIATION is done on my custom board 

Remember : I am using Internal PHY.

Looking forward to hear from you

Thanks!

 

Sanyam,

It appears that you made two very similar posts in the Ethernet forum on this topic. To simplify things, I split one of your posts from the original thread and joined the two posts into this new thread.

As I understand the situation, you performed the PHY level debug steps described in the original post (e2e.ti.com/.../395948) and determined that the voltages and resistances looked correct. You also note that you are able to link and communicate when you use different processor code.

Based on this, I believe the TMC4 Microcontrollers Forum is the best place for you to get help with your questions. I have therefore moved your post to this forum.

Patrick

Hello Sanyam

What about the MAC ID?

Regards
Amit

Hello Amit,
MAC ID is configured correctly by using UNIFLASH tool. But now problem is solved...There was an issue with ethernet connector......

Thanks

Hello Sanyam,

And could you elaborate with the solution?

Regards
Amit

The issue was with the SLVU2.8-4 IC which is connected in between Transformer(HX1188NLT) and ethernet connector. This IC was open.....