Customizing the Ethernet 10G MAC

The core has parameters so you can customize its function. You set the parameters in the General tab of the core's IP Configuration window.

Table 1. Ethernet 10G MAC Core Parameters
Name Options Description
Data Streaming Mode Cut Through, Store Forward Default: Cut Through
In Cut Through mode, the XGMII packet is transferred with minimum latency, without waiting for the complete packet.
In Store Forward mode, the XGMII packet is only transferred when the entire packet is fully stored.
Programmable Inter Packet Gap 9 - 15
Default: 12
In Store Forward mode, the effective IPG may be governed by the Store Forward mechanism, in which the packet is transferred only after it is fully stored.
Maximum Transmission Unit Frame Length 64 - 16,406 Default: 1518
Maximum Transmission Unit Frame Length is the total count of headers (destination address, source address, VLAN tag, type/length), data payload and frame check sequence.
Refer to the frame length depicted in Figure 1 and Figure 2.
Any RX packet with physical length > Maximum Transmission Unit Frame Length is flagged as an oversized frame.
Any RX packet with a payload < 46 (or < 42 for VLAN-tagged frames) is flagged as an undersized frame.
Configure MAC Source Address Thru Port Yes, No Default: No
When set to No, the user configures the MAC Source Address in the IP Manager Configuration GUI.
When set to Yes, the input port mac_source_address_port[47:0] is generated to facilitate the user’s input. The MAC Source Address configuration field in the IP Manager Configuration GUI becomes unavailable.
Additionally, when set to Yes, the user needs to drive static (or pseudo-static) values in hexadecimal to the input port mac_source_address_port[47:0]. This input value is used in the following scenarios:
  • When generating TX Pause frame
  • When comparing against address filtering
However, this input value is not used when converting from user TX AXI ST inputs to XGMII TX packets.
MAC Source Address – Default: 48'h0000_0000_0000
This configuration is only available if the Configure MAC Source Address Thru Port is set to No.
This setting is in hexadecimal. This MAC Source Address is used in the following scenarios:
  • When generating a TX pause frame.
  • When comparing it to address filtering.
This MAC Source Address is not used when converting from user TX AXI ST inputs to XGMII TX packets.
Broadcast Filtering Enable, Disable Default: Enable Broadcast Filtering.
Disable Broadcast Filtering.
TXFIFO Depth 8, 16, 32, 64, 128, 256, 512, 1024, 2048 Default: 512
Set the FIFO depth for storing the Full TX packet during Store Forward mode.
The FIFO depth must be large enough to store the maximum length of the TX frames intended for transfer.
Refer to Store Forward Mode.
This parameter is ineffective in Cut Through mode.
Link Fault Detection Enable, Disable Default: Enable Link Fault Detection.
Disable Link Fault Detection.
Optimize Timing Yes, No Default: Yes.
This enables the synthesis of pipeline registers to improve timing.
When choosing No, no pipeline registers are being synthesized. You can disable if the mac10gbe_clk in your design is meeting the targeted 156.25 MHz.