Altera High-Speed Development Kit, Stratix GX Edition - Manual (Page 133)

Altera Corporation Quartus II Version 3.0 8–5
Stratix GX SPI-4.2 Demonstration with 10-Port Gigabit Ethernet MAC
9. Soft-reset the Stratix GX development board by pressing S5.
1
Do not press S15 (labeled reset on the board) or the device
will lock up.
10. Start Ethernet traffic incrementally. Traffic from a Gigabit Ethernet
tester should have ports enabled one at a time for the Multi-PHY
core.