SBC-C20
SBC-C20 User Manual - Rev. First Edition: 1.0 - Last Edition: 1.0 - Author: A.R. - Reviewed by C.M. -Copyright © 2020 SECO S.p.A.
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M.2 Socket 2 Key B Slot
SBC-C20 provide a M.2 WWAN Slot, which allow the
connection of Connectivity modules, using PCI-e
interface or USB 2.0 interface.
The connector used for the M.2 WWAN slot is CN26,
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.
It is possible to place directly modules in 2260 size, buy
using the tallest Threaded Spacer mounted onboard.
It is possible to place also modules in 2242 / 3042 size,
by using a M/F Spacer which allow fixing the module on the lower spacer soldered on the PCB,
deemed for the fixing of shorter modules.
Here following the signals related to the PCI-e interface:
PC/PCIe1_Tx0-: PCI Express port #1 lane #0, Transmitting Output Differential pair
PC/PCIe1_Rx0-: PCI Express port #1 lane #0, Receiving Input Differential pair
DIF1#_REF_CLK / DIF1_REF_CLK: PCI Express Reference Clock for lane #0, Differential Pair
PCIE_RST#: Reset Signal that is sent from the i.MX8M processor to the PCI-e devices available
on the module. It is a VDD_3P3V active-low signal.
PCIe_CLQREQ#: PCI Express Clock Request Input, active low signal, electrical level
VDD_3P3V. This signal shall be driven low by any module inserted in the connectivity slot, in
order to ensure that the SoC makes available the reference clock.
VDD_3P3V active low signal. It must be externally driven by
the Connectivity module plugged in the slot when it requires waking up the system.
Here following the signals related to the USB interface:
/USB_P2-: USB 2.0 Port #2 differential pair. It is managed by the optional SMSC
2.
M.2 WWAN Slot (Socket 2 Key B type 3042/2260- CN26)
Pin
Signal
Pin
Signal
1
---
2
VDD_3P3V
3
GND
4
VDD_3P3V
5
GND
6
---
7
USB_P2-
8
W_DISABLE1#
9
10
---
11
GND
20
---
21
---
22
---
23
---
24
---
25
---
26
---
27
GND
28
---
29
---
30
UIM_RESET
31
---
32
UIM_CLK
33
GND
34
UIM_DATA
35
---
36
UIM_PWR
37
---
38
---
39
GND
40
---
41
PC
42
---
43
PCIe1_Rx0-
44
---
45
GND
46
---
47
PCIe1_Tx0-
48
---
49
PC
50
PCIE_RST#
51
GND
52
PCIe_CLQREQ#
53
DIF1#_REF_CLK
54
PCIe_WAKE#
55
DIF1_REF_CLK
56
---
57
GND
58
---
