Voltage Supply - Xilinx Spartan-3 User Manual

Voltage Supply

when an overflow occurs. If the mouse moves continuously, the 33-bit transmissions repeat
every 50 ms or so.
The L and R fields in the status byte indicate Left and Right button presses. A '1' indicates
that the associated mouse button is being pressed.
The following site contains additional information on interfacing to a PS/2-style mouse:
•
Voltage Supply
Most modern keyboards and mice work equally well from a 3.3V or 5V supply. The voltage
supply for the PS/2 port is selectable via the JP2 jumper, indicated as
located immediately above the PS/2 connector along the right edge. The 3.3V setting is
preferred as the FPGA's output signals operate from the 3.3V supply. The JP2 jumper
should be positioned as shown in
Table 6-5: PS/2 Port Supply Voltage Options
Some older keyboards and mice are 5V only. Consequently, the JP2 jumper should be set
for 5V operation as shown in
the 270Ω series resistors on the PS/2 data and clock signals connected to the FPGA. See the
schematic in
Spartan-3 Starter Kit Board User Guide
UG130 (v1.1) May 13, 2005
The PS/2 Mouse Interface
http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/mouse/mouse.html
PS/2 Port
Supply Voltage
3.3V
(DEFAULT)
5V
Figure A-7 for more details.
www.xilinx.com
1-800-255-7778
Table 6-5 by default.
Jumper JP2
Setting
JP2
JP2
Table 6-5. The Spartan-3 FPGA can tolerate 5V signals due to
R
in Figure 1-2,
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