DE0-CV User Manual
22
www.terasic.com
May 4, 2015
KEY2, KEY3 and RESET_N of the Schmitt Trigger devices are connected directly to the Cyclone
V FPGA. Each push-button switch provides a high logic level when it is not pressed, and provides a
low logic level when depressed. Since the push-button switches are debounced, they are appropriate
for using as clocks or reset inputs in a circuit.
Figure 3-5 Connections between the push-button and Cyclone V FPGA
Pushbutton released
Pushbutton depressed
Before
Debouncing
Schmitt Trigger
Debounced
Figure 3-6 Switch debouncing
User-Defined Slide Switch
There are ten slide switches connected to FPGA on the board (See
Figure 3-7
). These switches are
not debounced, and are assumed for use as level-sensitive data inputs to a circuit. Each switch is
connected directly to a pin on the Cyclone V FPGA. When the switch is in the DOWN position
(closest to the edge of the board), it provides a low logic level to the FPGA, and when the switch is
in the UP position it provides a high logic level.
