For the communication between board-to-board, you may try use Serial Lite III Streaming Intel IP. The Serial Lite III Streaming Intel FPGA IP is a high speed serial communication protocol for board-to-board and application data transfer. It can support up to 28Gbps.
When using this IP, you should be aware that you must re-instantiate the IP to the target specific transceiver tiles due to the transceiver architecture differences. In shortly, you cannot migrate your design from Intel Stratix10 L-tile/H-tile devices to Intel Stratix 10 E-tile devices.
For further information about this IP, please do refer the link below, https://www.intel.com/content/www/us/en/docs/programmable/683330/17-0/introduction.html
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