GD82559ER — Networkin g Silicon

6.3.1Description

Auto-Negotiation selects the fastest operating mode (in other words, the highest common denominator) available to hardware at both ends of the cable. A PHY’s capability is encoded by bursts of link pulses called Fast Link Pulses (FLPs). Connection is established by FLP exchange and handshake during link initialization time. Once the link is established by this handshake, the native link pulse scheme resumes (that is, 10BASE-T or 100BASE-TX link pulses). A reset or management renegotiate command (through the MDI interface) will restart the process. To enable Auto-Negotiation, bit 12 of the MDI Control Register must be set. If the PHY unit cannot perform Auto-Negotiation, it will set this bit to a 0 and determine the speed using Parallel Detection.

The PHY unit supports four technologies: 100BASE-Tx Full and Half Duplex and 10BASE-T Full and Half Duplex. Since only one technology can be used at a time (after every re-negotiate command), a prioritization scheme must be used to ensure that the highest common denominator ability is chosen. Each bit in this table is set according to what the PHY is capable of supporting. In the case of the 82559’s PHY unit, bits 0, 1, 2, 3, and 5 (10BASE-T, 10BASE-T full duplex, 100BASE-TX, 100BASE-TX full duplex and pause [frame based flow control], respectively) are set.

To detect the correct technology, the two register fields, technology ability and technology priority, should be ANDed together to obtain the highest common denominator. This value should then be used to map into a priority resolution table used by the MAC driver to use the appropriate technology.

6.3.2Parallel Detect and Auto-Negotiation

The PHY unit automatically determines the speed of the link either by using Parallel Detect or Auto-Negotiation. Upon a reset, a link status fail, or a Negotiate/Re-negotiate command, the PHY unit inserts a long delay during which no link pulses are transmitted. This period, known as Force_Fail, insures that the PHY unit‘s link partner has gone into a Link Fail state before Auto- Negotiation or Parallel Detection begins. Thus, both sides (PHY unit and PHY unit’s link partner)

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Intel GD82559ER manual Description, Parallel Detect and Auto-Negotiation
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GD82559ER specifications

The Intel GD82559ER is a highly regarded network interface controller (NIC) designed for use in various computing environments, primarily for stable connectivity in both desktop and server applications. Released as part of the 82559 family of Ethernet controllers, the GD82559ER features advanced technologies that enhance performance, reliability, and manageability.

One of the standout features of the 82559ER is its ability to support both 10/100 Mbps Ethernet. This dual capability allows the controller to operate in a wide range of network settings, making it adaptable to legacy systems while also providing support for modern Ethernet standards. This versatility is crucial for organizations looking to maintain operational effectiveness without the need for immediate upgrades to their existing infrastructure.

The GD82559ER employs a PCI interface, which allows it to connect with various devices and motherboards easily, making it a go-to choice for manufacturers aiming for integration in their systems. It also includes features like Auto-Negotiation, enabling the NIC to automatically detect and select the appropriate speed and duplex mode for optimal performance. This capability is essential in dynamic networking environments, where devices from various generations coexist.

Power management is another critical aspect of the GD82559ER. The controller supports advanced power-saving features like PCI Power Management, reducing energy consumption during low-usage periods. This not only contributes to lower operational costs but also aligns with modern eco-friendly initiatives in technology.

Additionally, the GD82559ER comes equipped with advanced diagnostics and monitoring capabilities. This enhances the network's manageability by allowing administrators to track performance metrics and diagnose issues effectively. Through its onboard diagnostics, the controller aids in ensuring a stable network connection, allowing for timely interventions when issues arise.

The controller is also designed with a robust architecture that supports various operating systems, facilitating a broad implementation across different platforms. As a result, the GD82559ER has become a reliable option for system builders and enterprises focused on building dependable networking solutions.

Overall, the Intel GD82559ER is a versatile, high-performance network interface controller that continues to serve as a foundational component for computer systems that require efficient, reliable networking capabilities. Its combination of technologies and features makes it a popular choice in diverse computing environments.
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