1.2.5.5 Ethernet GMAC Driver Library

The Ethernet Media Access Controller (GMAC) module implements a 10/100 Mbps Ethernet MAC, compatible with the IEEE 802.3 standard. The GMAC can operate in either half or full duplex mode at all supported speeds.

Embedded Characteristics

  • Compatible with IEEE Standard 802.3

  • 10, 100 Mbps operation

  • Full and half duplex operation at all supported speeds of operation

  • Statistics Counter Registers for RMON/MIB

  • MII interface to the physical layer

  • Integrated physical coding

  • Direct memory access (DMA) interface to external memory

  • Support for 6 priority queues in DMA

  • 8 KB transmit RAM and 4 KB receive RAM

  • Programmable burst length and endianism for DMA

  • Interrupt generation to signal receive and transmit completion, errors or other events

  • Automatic pad and cyclic redundancy check (CRC) generation on transmitted frames

  • Automatic discard of frames received with errors

  • Receive and transmit IP, TCP and UDP checksum offload. Both IPv4 and IPv6 packet types supported

  • Address checking logic for four specific 48-bit addresses, four type IDs, promiscuous mode, hash matching of unicast and multicast destination addresses and Wake-on-LAN

  • Management Data Input/Output (MDIO) interface for physical layer management

  • Support for jumbo frames up to 10240 Bytes

  • Full duplex flow control with recognition of incoming pause frames and hardware generation of transmitted pause frames

  • Half duplex flow control by forcing collisions on incoming frames

  • Support for 802.1Q VLAN tagging with recognition of incoming VLAN and priority tagged frames

  • Support for 802.1Qbb priority-based flow control

  • Programmable Inter Packet Gap (IPG) Stretch

  • Recognition of IEEE 1588 PTP frames

  • IEEE 1588 time stamp unit (TSU)

  • Support for 802.1AS timing and synchronization

  • Supports 802.1Qav traffic shaping on two highest priority queues