LTE Standard Module Series
EC20 R2.1 Mini PCIe Hardware Design
EC20_R2.1_Mini_PCIe_Hardware_Design 14 / 51
3
Application Interfaces
The physical connections and signal levels of EC20 R2.1 Mini PCIe comply with PCI Express Mini Card
Electromechanical Specification. This chapter mainly describes the definition and application of the
following interfaces for EC20 R2.1 Mini PCIe:
Power supply
UART interfaces
USB interface
(U)SIM interfaces
PCM and I2C interfaces
Control and Indication signals
3.1. Pin Assignment
The following figure shows the pin assignment of EC20 R2.1 Mini PCIe module. The top side contains
EC20 R2.1 module and antenna connectors.
PIN2
PIN52
BOT
PIN1
PIN51
TOP
Pin Name
Pin No.
WAKE#
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
51
COEX_UART_RX
COEX_UART_TX
RESERVED
GND
UART_RX
UART_TX
GND
RI
RESERVED
GND
UART_CTS
UART_RTS
GND
GND
DTR
RESERVED
GND
GND
VCC_3V3
VCC_3V3
GND
PCM_CLK
PCM_DOUT
PCM_DIN
PCM_SYNC
Pin Name
Pin No.
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
VCC_3V3
GND
NC
USIM_VDD
USIM_DATA
USIM_CLK
USIM_RST
RESERVED
GND
W_DISABLE#
PERST#
RESERVED
GND
NC
I2C_SCL
I2C_SDA
GND
USB_DM
USB_DP
GND
LED_WWAN#
USIM_PRESENCE
RESERVED
NC
GND
VCC_3V3
Figure 2: Pin Assignment