50G Interlaken Intel® FPGA IP User Guide

ID 683217
Date 10/31/2022
Public
Document Table of Contents

3.6. Transfer Mode Selection

The Transfer mode selection parameter specifies whether the 50G Interlaken transmitter expects incoming traffic to the TX user data transfer interface to be interleaved or packet based. The supported values are Interleaved and Packet. Interleaved mode is also called Segmented mode. The value of this parameter cannot be modified dynamically; it is determined when you generate the IP core.

If the value of this parameter is Packet, the 50G Interlaken transmitter expects incoming traffic to the TX user data transfer interface to be packet based. This setting enables the internal enhanced scheduler and causes the IP core to send data on the Interlaken link based on the programmed BurstMax and BurstMin parameter settings.

If the value of this parameter is Interleaved, the 50G Interlaken transmitter expects you to provide Start of Burst (SOB) and End of Burst (EOB) indications with the data on the TX user data transfer interface. In Interleaved mode, you can send either packet-based traffic or interleaved traffic, but you must provide the correct SOB and EOB signals even when sending non-interleaved packets. In this mode, the IP core does not implement the enhanced scheduler. The IP core ignores the BurstMax and BurstMin values. BurstShort is still in effect. To avoid overflowing the transmit FIFO, you should not send a burst that is longer than 1024 bytes.

If packets are always sent contiguously in your application, Intel® recommends that you set this parameter to the value of Packet. This setting enables simpler transfers on the user data transfer interface, and enables the 50G Interlaken IP core to perform enhanced scheduling based on the BurstMax and BurstMin settings. If the data bursts that arrive on the TX application interface might be interleaved between channels, then you must set Transfer mode selection to the value of Interleaved.

The default value of the Transfer mode selection parameter is Interleaved.