HUAWEI ME909 Series LTE LGA Module
Hardware Guide
Description of the Application Interfaces
Issue V0.3 (2013-05-21)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
31
Figure 3-12
Driving circuit
3.5 UART Interface
3.5.1
Overview
The ME909 module is projected to provide two UART interfaces for asynchronous
communication channels. They are UART0 (4-wire UART) and UART1 (4-wire UART).
But now due to software schedule, UART0 can be only used as 2-wire UART, and
UART1 is not supported at the moment.
The UART2 (2-wire UART) is for debugging only. Customer should layout two test
points for them in case system trouble shooting and analysis.
Table 3-7 lists the UART interface signals.
Table 3-7
UART interface signals
Pin
No.
Pin Name
I/
O
Description
DC Characteristics (V)
Min.
Typ.
Max.
76
UART0_TX
O UART0 transmit output
–0.3
1.8
2.1
78
UART0_RX
I
UART0 receive data input
–0.3
1.8
2.1
74
UART0_RTS
O UART0 Ready for receive
–0.3
1.8
2.1
80
UART0_CTS
I
UART0 Clear to Send
–0.3
1.8
2.1
1
UART1_TX
O UART1 transmit output
–0.3
1.8
2.1
2
UART1_RTS
O UART1 Ready for receive
–0.3
1.8
2.1
3
UART1_CTS
I
UART1 Clear to Send
–0.3
1.8
2.1
