Nexys2 Reference Manual
Digilent
www.digilentinc.com
Copyright Digilent, Inc.
Page 15/17
Doc: 502-134
Peripheral Connectors
The Nexys2 board provides four two-row 6-pin Pmod connectors that together can accommodate up
to 8 Pmods. The four 12-pin connectors each have 8 data signals, two GND pins, and two Vdd pins.
All data signals include short circuit protection resistors and ESD protection Diodes. A jumper block
adjacent to each Pmod connector can connect the Pmod’s Vdd signal to the Nexys2 board’s 3.3V
supply or to the input power bus (VU). If the jumper is set to VU and USB power is driving the main
power bus, care should be taken to ensure no more than 200mA is consumed by the Pmod. Further, if
the jumper is set to VU, a voltage source connected to the Pmod can drive the main power bus of the
Nexys2 board, so care should be taken to avoid connecting conflicting power supplies.
The Pmod connectors are labeled JA (nearest the power jack), JB, JC, and JD (nearest the expansion
connector). Pinouts for the Pmod connectors are provided in the table below.
More than 30 low-cost are available for attachment to these connectors. Pmods can either be
attached directly, or by using a small cable. Available Pmods include A/D and D/A converters, motor
drivers, speaker amplifiers, distance measuring devices, etc. Please see
www.digilentinc.com
for
more information.
Table 3: Nexys2 Pmod Connector Pin Assignments
Pmod JA
Pmod JB
Pmod JC
Pmod JD
JA1: L15
JA7: K13
JB1: M13
JB7: P17
JC1: G15
JC7: H15
JD1: J13
JD7: K14
1
JA2: K12
JA8: L16
JB2: R18
JB8: R16
JC2: J16
JC8: F14
JD2: M18
JD8: K15
2
JA3: L17
JA9: M14
JB3: R15
JB9: T18
JC3: G13
JC9: G16
JD3: N18
JD9: J15
3
JA4: M15
JA10: M16
JB4: T17
JB10: U18
JC4: H16
JC10: J12
JD4:; P18
JD10: J14
4
Notes:
1
shared with LD3
2
shared with LD3
3
shared with LD3
4
shared with LD3
1
5
JA
Spartan 3E
FPGA
JA1
JA2
JA3
JA4
ESD protection
diodes
1
Resistors for short-
circuit protection
Power supply
jumper
VU
3.3V
JA5
JA6
JA7
JA8
7
2
8
3
9
4
10
5
11
6
12
Figure 23: Nexys2 Pmod connector circuits
