Forum Discussion
Honored ContributorEthernet link speed auto detection
Hi
I have a custom board with a ethernet PHY connected to the FPGA using RGMII. I am using triple speed ethernet and iniche. I do not have the signals set_10 and set_1000 from the PHY. I can get the network to work on either 1000 or 100 by connecting eth_mode to 1 or 0 or using the ETH_SPEED bit in the command_config register. How can I get it to auto detect the link speed?16 Replies
Altera_ForumOk, but the problem is that I do not have those inputs (set_1000 and set_10) to the FPGA and I am wondering if there is another way to detect the link speed.
- Altera_Forum
Those pins are not dependent on MII/GMII/RGMII bus and are valid for all types. Check the RGMII bus specification.
- Altera_Forum
Thank you. Figure 4-12 on page 4-24 is for MII/GMII interface. I am using a RGMII interface so I think the correct figure should be 4-13. My logic is as shown in 4-13 with set_1000 and set_10 tied to 0 in the FPGA. With this logic I can use the MAC in 1000 or 100, but I have to manually select the speed with the ETH_SPEED bit in the command_config register. What I am looking for is a way to make the MAC or iniche detect the ethernet link speed without using the set_1000 input.
- Altera_Forum
figure 4-12 on page 4-24
- Altera_Forum
Thank you, but I would not have asked before looking there.
I guess I just have missed it then. I will have another look, hopefully I will find it this time. - Altera_Forum
Read the triple speed ethernet user guide pdf! It's all written and shown there.
