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.
41
3.10 JTAG Interface
The ME909u-521 module provides Joint Test Action Group (JTAG) interface. Table
3-11 shows the signals on the JTAG interface. It is recommended that route out the 9
pins as test points on the DTE for tracing and debugging.
Table 3-11
Signals on the JTAG interface
Pin
No.
Pin Name
Pad
Type
Description
Parameter Min.
(V)
Typ.
(V)
Max.
(V)
Comments
30
JTAG_TMS
I
JTAG test mode select
V
IH
1.17
1.8
2.1
-
V
IL
–0.3
-
0.63
-
36
JTAG_TRST_N I
JTAG reset
V
IH
1.17
1.8
2.1
-
V
IL
–0.3
-
0.63
-
42
JTAG_TCK
I
JTAG clock input
V
IH
1.17
1.8
2.1
-
V
IL
–0.3
-
0.63
-
72
JTAG_TDO
O
JTAG test data output
V
OH
1.35
1.8
1.8
-
V
OL
0
-
0.45
-
87
JTAG_TDI
I
JTAG test data input
V
IH
1.17
1.8
2.1
-
V
IL
–0.3
-
0.63
-
93
JTAG_RTCK
O
JTAG return clock
V
OH
1.35
1.8
1.8
-
V
OL
0
-
-
-
14
PS_HOLD
I
Power supply hold
signal to PMU, used
for JTAG
V
IH
1.17
1.8
2.1
-
V
IL
–0.3
-
0.63
-
47
JTAG_SRST_N
I
JTAG reset for
debugging
V
IH
1.17
1.8
2.1
-
V
IL
–0.3
-
0.63
-
32
VCC_EXT1
PO
1.8 V POWER output
-
1.75
1.8
1.85
-
It is recommended that customer route out the JTAG pins on the DTE board as test points for
debugging.
