Page 22
X1
32.768KHz
C2
10pF
C3
10pF
RTC_X1
RTC_X2
C7
18pF
C6
18pF
X2
12MHz
X1
X2
VCC-3.3V
75
74
73
72
71
70
69
68
67
66
64
65
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
9
11
12
4
3
78 77
24
23
18
17
16
15
14
13
5
6
7
8
10
79
80
1
2
22
21
20
19
25
76
FTDI
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
10
0
ST
ES
TR
ES
TN
RE
SE
TN
VP
P
FS
O
U
RC
E
G
PI
O
52
G
PI
O
51
GPIO21
GPIO22
GPIO23
GPIO24
D_DM
VCC3V3
VCC1V2
GPIO0
G
PI
O
54
G
PI
O
53
GPIO63
GPIO64
GPIO65
GPIO66
G
PI
O
55
G
N
D
G
PI
O
10
G
PI
O
9
G
PI
O
8
G
PI
O
12
G
PI
O
7
G
PI
O
6
RT
C_
XI
O
TX
O
N
GPIO20
GPIO19
G
PI
O
14
G
PI
O
13
D
AC
_R
EF
P
VC
C3
V3
AG
N
D
G
PI
O
11
GPIO28
G
PI
O
44
GPIO39
GPIO38
GPIO37
GPIO36
GPIO35
GPIO34
DRREF
D_DP
GPIO62
GPIO61
GPIO30
GPIO27
GPIO26
G
PI
O
48
G
PI
O
15
G
PI
O
16
GPIO17
GPIO18
G
PI
O
43
G
PI
O
42
GPIO41
GPIO40
G
PI
O
57
G
PI
O
58
XIO
GPIO4
VC
C3
V3
G
PI
O
56
GPIO1
G
PI
O
49
GPIO2
GPIO5
NC
GPIO33
GPIO32
GPIO31
D
EB
U
G
G
PI
O
50
GPIO3
XI/CLKIN
RT
C_
XI
/R
TC
_C
LK
IN
G
PI
O
47
G
PI
O
46
G
PI
O
45
GPIO29
GPIO25
VCC1V2
VCC3V3
H_DM
RR
EF
SE
T
VC
C3
V3
H_DP
AGND
HRREF
VC
C1
V2
VC
C3
V3
RX
IP
RX
IN
TX
O
P
G
PI
O
60
FT900Q
0
TP
U1
R30
VCC-1.2V
FSRC
R35
10K
R36
10K
VCC-3.3V
C42
100nF
0Ω
C8
100nF
VCC-3.3V
C9
100nF
VCC-3.3V
C10
100nF
VCC-3.3V
VCC-3.3V
C13
100nF
C39
100nF
VCC-1.2V
C41
4.7uF
VCC-1.2V
C38
10uF
VCC-1.2V
C5
100nF
VCC-1.2V
Figure 6-3: Crystal oscillator schematic