Configuring Finisar Copper SFP 8521-3
This page explains how to configure Finisar Copper SFP 8521-3 to talk to Altera Triple-Speed Ethernet IP Core. If you use other Altera 1G Ethernet PHY IP Cores, this page still help you to understand how the PCS registers have to be set.
1000BASE-X Auto-Negotiation On configuration (No register write required)
The default setting of Finisar 8521-3 Copper SFP is 1000BASE-X Auto-Negotiation. If you use 1000BASE-T as the copper link, you don't need to access SFP's registers.
Link steps
- The Triple-Speed Ethernet (TSE) IP Core and the SFP start talking each other, but RJ-45 cable is still disconnected and the copper (10BASE-T/100BASE-TX/1000MBASE-T)link is not established. Because of the copper link status, the Finisar SFP sends its 1000BASE-X ability 0x0000 to the TSE (TSE's rx_frame = 0xBC420000BCB50000).
- TSE’s link partner ability status register (0x85) is also 0x0000.
- A RJ-45 cable is attached and the Finisar SFP establishes the copper link at 1000M
- The TSE and the Finisar SFP complete 1000BASE-X Auto-Negotiation, and TSE's led_an goes 1.
Note: Because acceptable link speed is only 1000M, auto-negotiation won’t be completed if copper link speed is 10M or 100M.
SGMII Auto-Negotiation On configuration (Register write required)
Conguring the TSE to SGMII Auto-Negotiation mode
- TSE PHY address offset 0x12 = 0x12D0
- TSE PHY address offset 0x13 = 0x0003
- TSE PHY address offset 0x14 = 0x0003
- TSE PHY address offset 0x00 = 0x1140
- TSE PHY address offset 0x00 = 0x9140
At this point, the Finisar Coppper SFP is still in 1000BASE-X Auto-Negotiation mode. Because of the mismatch setting, the auto-negotiation won’t be completed (TSE's led_an remains at 0).
Configuring Finisar Copper SFP to SGMII Auto-Negotiation too, and advertise 10M, 100M, and 1000M for the copper link
- SFP address offset 0x1B = 0x9084 (Enable SGMII mode)
- SFP address offset 0x09 = 0x9084 (Advertise 1000BASE-T Full and Half duplex)
- SFP address offset 0x04 = 0x0DE1 (Advertise 10BASE-T/100BASE-TX Full and Half duplex)
- SFP address offset 0x00 = 0x8140
- SFP address offset 0x00 = 0x9140 (Software reset)
Link Steps
- An RJ-45 cable is connected to the Copper SFP, and copper link is established at 1000M, and the SGMII Auto-Negotiation is completed (TSE's led_an goes 1).
- TSE's SGMII MAC mode link partner ability status register is 0xd801 (Copper link up at 1000M)
- Disconnect the RJ-45 cable
- Copper link is down. The SGMII auto-negotiation is still established (TSE's led_an is 1), the Finisar SFP sends its ability 0x4001 (Copper link down), and TSE's partner ability register reflects it to its register address offset 0x05.
- Reconnect the RJ-45 cable
- Copper link is re-established at 100M. The Finisar SFP sends its ability 0xd401 (Copper link up at 100M), and TSE’s partner ability register reflects it to its register address offset 0x05.
