HUAWEI ME909u-521 LTE LGA Module
Hardware Guide
Description of the Application Interfaces
Issue 05 (2017-12-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
40
The ME909u-521 module PCM interface enables communication with an external
codec to support linear format.
Figure 3-17
Circuit diagram of PCM interface (ME909u-521 module is used as PCM
master)
PCM_SYNC: Output when PCM is in master mode;
PCM_CLK: Output when PCM is in master mode;
The PCM function of ME909u-521 module is only supported in master mode.
It is recommended that a TVS be used on the related interface, to prevent electrostatic
discharge and protect integrated circuit (IC) components.
The signal level of CODEC must match that of the ME909u-521 module.
3.9 General Purpose I/O Interface
The ME909u-521 module provides GPIO pins for customers to use for controlling
signals which are worked at 1.8 V CMOS logic levels. Customers can use AT
command to control the state of logic levels of GPIO output signal. About the details of
GPIO command
,
see the
HUAWEI ME909u-521 LTE LGA Module AT Command
Interface Specification
.
Table 3-10
Signals on the GPIO interface
Pin No.
Pin
Name
Pad
Type
Description
Parameter
Min.
(V)
Typ.
(V)
Max.
(V)
Comments
51, 55,
105, 109,
113
GPIO
I/O
General Purpose I/O
pins. The function of
these pins has not
been defined.
V
OH
1.35
1.8
1.8
-
V
OL
0
-
0.45
-
V
IH
1.17
1.8
2.1
-
V
IL
–0.3
-
0.63
-
