TSE PHY Loopback

Hi everyone,

We are using Arria V GX FPGA, and the IP Core TSE 1000Base-X/SGMII with PCS and PMA. I am trying to activate the PHY loopback but couldn’t get it to work as it’s my first time to work with Ethernet.

The sequence is as follows:

1. Write to PCS Control register 0x00 : “0100000101100000”

So I enable the Uniderectional option to be able to send data without a link partner

Activate gigabit mode

Activate loopback mode

1. If_Mode register 0x14 : "0000000000001001"

SGMII_ENA set to 1, USE_SGMII_AN set to 0, SGMII_SPEED to gigabit mode

1. Then I reset the PCS by setting bit 15 of control register to 1

Can I afterwards start to write data by setting the gmii_tx_clk_en to 1 and writing a byte to gmii_tx_d without having a valid link? Or I still need to do something because currently I don’t see any data on rx. I also read the PCS registers and confirmed that they were correctly written.

Thanks in advance.