C H A P T E R  1

The eri Device Driver

The eri device driver handles the SUNW,eri device on Sun systems using the RIO ASIC.

This chapter includes the following sections:

• Hardware Overview

• Operating Speeds and Modes

• Auto-Negotiation

---

Hardware Overview

The SUNW,eri device provides a 100BASE-TX network interface using the Ethernet function of the RIO ASIC. The driver automatically sets the link speed to 10 or 100 Mbps and conforms to the 100BASE-T IEEE 802.3u Ethernet Standard. The RIO ASIC provides the PCI interface and Media Access Control (MAC) functions. The internal transceiver, which connects to an RJ-45 connector, provides the physical layer functions.

The RIO ASIC is a chip set composed of an I/O chip and a single chip Ethernet transceiver; the eri device driver uses the Ethernet function of this ASIC.

---

Operating Speeds and Modes

You can operate the link in any of the following speeds and modes with the SUNW, eri device:

• 100 Mbps, full-duplex

• 100 Mbps, half-duplex

• 10 Mbps, full-duplex

• 10 Mbps, half-duplex

The 100BASE-T IEEE 802.3u Ethernet Standard describes these speeds and modes.

---

Auto-Negotiation

A key feature of the Sun eri FastEthernet driver is auto-negotiation. The auto-negotiation protocol, as specified by the 100BASE-T IEEE 802.3u Ethernet Standard, selects the operation mode (half-duplex or full-duplex), and the auto-sensing protocol selects the speed (10 Mbps or 100 Mbps) for the adapter. Further information can be found in Appendix A, Auto-Negotiation.