Digilent FX12 - Manual (Page 15)

Digilent
FX12 Reference Manual
www.digilentinc.com
Copyright Digilent, Inc. Page 15/18 Doc: 502-046
FX12 Serial Port Circuit Diagram
Other User I/O
Eight LEDs, four pushbuttons, and two SMA connectors are provided for general user I/O. Pushbutton
inputs are normally low, and they are driven high only when the pushbutton is pressed. Anodes of the
high-bright LEDs are connected to FPGA pins, so that a logic high signal will illuminate them with just
3-4mA of current. Separate LEDs are provided for power-on indication and successful completion of
FPGA configuration. The two SMA connectors provide a differential pair of I/O’s suitable for high-
frequency signals such as clocks.
SMA connectors
for (differential)
clock inputs
8 LEDs
4 Pushbuttons
Virtex-4
FPGA
LD0
LD1
LD2
LD3
LD4
LD5
T3
U3
U2
N2
P5
P4
P2
R2
LD6
LD7
BTN0
BTN1
BTN2
BTN3
SMA
Connectors
CLKP
CLKN
User
LEDs
User
Push-
buttons
T4
R5
R6
R3
R4
R1
User I/O Devices Circuit Diagram