Requirements
2-18
AT91CAP9-STK Starter Kit User Guide
6351B–CAP–27-Jun-08
2.4.1.4
F4: RS232 Driver
An ADM3202 RS232 driver is implemented for signal adaptation between RS232 signals (RXD, TXD) on
the debug port connector and AT91CAP9 Debug unit 3.3V signals (DRXD, DTXD).
The implementation is shown below:
2.4.1.5
F5: USB Host and Device
2.4.1.5.1 USB Host
The two USB v2.0 Host interfaces are managed by the AT91CAP9 USB Host port, which handles OHCI
protocol as well as USB v2.0 Full-speed and Low-speed protocols.
Two NUF2101 USB filters are implemented for ESD protection and line adaptation (26.3
Ω
to 33.7
Ω
).
One 0603 footprint is implemented on each signal to adjust 39
Ω
line impedance if necessary.
One 500 mA SMD fuse is added on 5V power supply of each port.
TXD
RXD
DRXD
DTXD
J34
SUBD9_M_C
5
9
4
8
3
7
2
6
1
10
11
C1+
V+
VCC
C1-
C2+
C2-
V-
T
T
R
R
GND
U10
ADM3202ARNZ
1
16
3
4
5
15
11
10
12
9
8
13
7
14
2
6
C119
100nF
1
2
C121
100nF
1
2
C122
100nF
1
2
C120
100nF
1
2
C123
100nF
1
2
3V3
R62
100K
R63
0R
3V3
R64
1K
R65
0R
3V3
R154
0R
R153
0R
TP67
1
R98
0R
5V
HDMA
HDP A
HDMB
HDP B
C144
10uF_1210
1
2
C145
100nF
1
2
F1
0A5_13V 2
1
2
5V
C148
100nF
1
2
C149
100nF
1
2
D+IN
D+OUT
D-OUT
D-IN
L11
NUF2101MT1G
1
3
6
4
2
5
D+IN
D+OUT
D-OUT
D-IN
L12
NUF2101MT1G
1
3
6
4
2
5
R223
0R
R99
0R
R226
0R
C146
100nF
1
2
C147
10uF_1210
1
2
F2
0A5_13V 2
1
2
5V
5V
A
B
J37
A1
A4
A2
A3
FIX1
FIX2
B1
B2
B3
B4
FIX3
FIX4
R224
0R
R225
0R