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Lattice Semiconductor 1GbE PCS IP Core User’s Guide
The Auto-negotiation function that allows a device (local device) to advertise modes of operation it possesses to a
device at the remote end of a link segment (link partner) and to detect corresponding operational modes that the
link partner may be advertising. The Auto-negotiation function exchanges information between two devices that
share a link segment and automatically configures both devices to take maximum advantage of their abilities.
Management Interface
The MDIO Management Interface is implemented based on specifications in Clause 22 of the IEEE 802.3-2002
standard.
The management interface is used to connect a management entity and a managed PHY for the purposes of con-
trolling the PHY and gathering status from the PHY. The management interface consists of a pair of signals that
physically transport the management information across the GMII, a frame format and a protocol specification for
exchanging management frames, and a register set that can be read and written using these frames.
GMII Interface
This module, depending on the configuration, provides a GMII Interface or a connection to an on-chip MAC.
ORT42G5 Interface
This section provides the following functions:
• A bridging function between the 8-bit PCS core and the 32-bit Application Specific Block (ASB). The data rate
translation cross the two clock domains is achieved using asynchronous FIFOs.
• Clock compensation to a tolerance of +/- 100 ppm between the recovered clock and IP system clock. This is
done by insertion or deletion of idle characters.
• Logic to program the control registers inside the ASB through the system bus User Master Interface.
Design Parameters
Table 1. Parameter Descriptions
Parameter
Description
GMII_INF
If this parameter is set to “yes”, a GMII interface will be provided through the
FPGA I/Os to an external device. If this parameter is set to “no”, an internal
interface will be provided to a MAC on the same chip.
AUTO_NEG
If this parameter is set to “yes”, the Auto-negotiation module and Manage-
ment registers will be enabled. If this parameter is set to “no”, the Auto-
negotiation module and Management registers will be disabled.
MDIO_INF
The optional MDIO Interface is only available if the Auto-negotiation param-
eter is set to “yes”. If the MDIO parameter is set to “yes”, an MDIO interface
will be provided through the FPGA I/Os to an external device.
