The MRMAC architecture is composed of four independent Ethernet ports, each capable of 10/25GE data rate. The port resources can be dynamically combined to produce higher IEEE Ethernet rates, up to an overall bandwidth of 100GE. The ports can be statically configured through the IP wizard or dynamically configured during run-time through the AXI4-Lite interface.
A port data rate is configured using the ctl_data_rate_<N> field (N = 0...3) of each MODE_REG of the port. Values
are shown in the following table. All values not listed are reserved.
| Port | Configurable Modes (ctl_data_rate_<N>[2:0]) | ||||
|---|---|---|---|---|---|
| 10GE | 25GE | 40GE | 50GE | 100GE | |
| 0 | 000 | 001 | 010 | 011 | 100 |
| 1 | 000 | 001 | N/A | N/A | N/A |
| 2 | 000 | 001 | N/A | 011 | N/A |
| 3 | 000 | 001 | N/A | N/A | N/A |
|
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Port 0 can be configured to operate at 10GE, 25GE, 40GE, 50GE, or 100GE data rates. However, when operating at 50GE data rate, port 0 consumes the data path resources of port 1, making it unavailable for independent operation. When port 0 is configured for 40GE or 100GE data rate operation, all internal data path resources are consumed. Consequently, ports 1, 2, and 3 are unavailable for independent operation.
Similarly, when port 2 is configured to operate at 50GE data rate, it consumes the data path of port 3, making port 3 unavailable for independent operation. Modes can be mixed-and-matched. For example, the user logic could configure ports 0 and 1 as 10GE and 25GE respectively, and then configure port 2 as a single 50GE client.
A change in the MODE_REG register of any port requires a reset to be issued to that port after configuration is complete.