Terasic TSOM, Manual

Page: 29 / 62

TSoM Evaluation
Kit User Manual 28
www.terasic.com
July 26, 2019
Chapter 5
FPGA Fabric
Components
This section describes the interfaces connected to the FPGA. Users can control or monitor different
interfaces with user logic from the FPGA.
5
5
.
.
1
1
U
U
s
s
e
e
r
r
P
P
u
u
s
s
h
h
-
-
b
b
u
u
t
t
t
t
o
o
n
n
s
s
,
,
S
S
w
w
i
i
t
t
c
c
h
h
e
e
s
s
a
a
n
n
d
d
L
L
E
E
D
D
s
s
The TSoM Based Board has two push-buttons connected to the FPGA, as shown in Figure 5-1 .
Schmitt trigger circuit is implemented and act as switch debounce in Figure 5-2 for the
push-buttons connected. The two push-buttons named KEY0 and KEY1 coming out of the Schmitt
trigger device are connected directly to the Cyclone V SoC FPGA. The push-button generates a low
logic level or high logic level when it is pressed or not, respectively. Since the push-buttons are
debounced, they can be used as clock or reset inputs in a circuit.
Figure 5-1 Connections between the push-buttons and the Cyclone V SoC FPGA
Pushbutton released Pushbutton depressed
Before
Debouncing
Schmitt Trigger
Debounced
Figure 5-2 Switch debouncing
There are two slide switches connected to the FPGA, as shown in Figure 5-3 . These switches
are not debounced and to be used as level-sensitive data inputs to a circuit. Each switch is