SM-B79
SM-B79 User Manual - Rev. First Edition: 1.0 - Last Edition: 1.0 - Author: A.R - Reviewed by M.B. - Copyright © 2021 SECO S.p.A.
53
3.3.13
M.2 WWAN Key B Slot
On SM-B79 carrier board, to add communications
functionality, it is available a dedicated M.2 Key B
Slot for WWAN connectivity (Modems), which allows
plugging modules with USB 2.0 and/or PCI-e x1
interface.
The connector used for the M.2 WWAN slot is
CN38, which is a standard 75 pin M.2 Key B
connector, type LOTES p/n APCI0087-P001A,
H=8.5mm, with the pinout shown in the table on the
left.
On-board there is also a Threaded Spacer which allows the placement of M.2
Socket 2 Key B WWAN modules in 2260 or 3042 size.
Please be aware that PCI-e interface will be available on this slot only if:
Used SMARC
®
modules offer at least 1x PCI-e x1 interface (since it is connected to
PCI-e port #A), AND configure properly 2-4 position of the dual DIP switch SW17,
according to the table at par.3.3.11
M.2 WWAN Slot (Socket 2 Key B type 2260/3042) CN38
Pin Signal
Pin Signal
1
---
2
+3.3V_ALW
3
GND
4
+3.3V_ALW
5
GND
6
+1.8V_ALW (2k2 pull-up)
7
USB5+
8
W_DISABLE1#_B
9
USB5-
10
M2_KEYB_LED
11
GND
20
---
21
---
22
---
23
---
24
---
25
---
26
W_DISABLE2#_B
27
GND
28
---
29
---
30
UIM_RST#
31
---
32
UIM_CLK
33
GND
34
UIM_DATA
35
---
36
UIM_PWR
37
---
38
---
39
GND
40
---
41
PCIE_A_RX-_M2
42
---
43
PC_M2
44
---
45
GND
46
---
47
PCIE_A_TX-_M2
48
---
49
PC_M2
50
PCIE_A_RST#
51
GND
52
PCIE_A_CLKREQ#
53
PCIE_A_CLK-_M2
54
PCIE_WAKE#
55
PCI_M2
56
---
57
GND
58
---
59
---
60
---
61
---
62
---
63
---
64
---
65
---
66
---
67
---
68
---
69
---
70
+3.3V_ALW
71
GND
72
+3.3V_ALW
73
GND
74
+3.3V_ALW
75
---