The Gigabit Ethernet MAC Module (GEM_GXL) is compatible with the IEEE 802.3 Ethernet Standard and supports 10/100/1000M triple speed operation. It supports MII, GMII, RGMII and TBI interfaces to an external PHY interface; AHB and AXI interfaces for DMA to external memory; an APB internal interface for its internal registers; and additional signals for reset, interrupt and test. The GEM_GXL also contains functionality to support 1588 time stamping, priority queuing, VLAN tagging and pause frames. If required, the GEM can be configured to operate with an external FIFO interface in applications where DMA is not a requirement. A PCS sub-layer is incorporated for 1000 Mbps operation and provides a TBI to the PMA layer. The PCS can be configured through the network configuration register to support an SGMII interface between the MAC and an external PHY.