2–24
Reference Manual
Altera Corporation
Stratix II GX EP2SGX90 Transceiver Signal Integrity Development Board
May 2006
Interfaces
lists the spread spectrum output selection DIP switch settings.
lists PCIe clock and quad transceiver clock DIP switch
settings.
1
Switches 7 and 8 are not connected.
Clock
S
electio
n
S
witche
s
(
S
9 a
n
d
S
10)
Switch S9 is used to control whether the clock input is driven from an
external or an on-board source. Switch S10 is used to apply power to the
board. The positions for these switches are labelled on the silk-screen.
lists clock selection switch settings for board reference S9.
Table 2–16. Spread Spectrum Output Selection Setting (S8)
Switch
Center =/-0.25
Down -0.5
Down -0.75
No Spread
SW3
Closed
Open
Closed
Open
SW4
Closed
Closed
Open
Open
Table 2–17. PCIe Clock & Quad Transceiver Clock DIP Switch Settings (S8)
PCIe Clock DIP Switch Setting
Quad Transceiver Clock DIP Switch Setting
Switch
Enable Clock
Disable Clock
Switch
Enable Clock
Disable Clock
SW5
Open
Closed
SW6
Open
Closed
Table 2–18. Clock Selection Switch (S9)
Switch Setting
Result
Switch in OSC setting
Selects the 156.25-MHz oscillator
Switch in SMA position
Selects external clock input