Huawei MU709s-2, Руководство по оборудованию

Страница: 45 / 86

HUAWEI MU709 Series HSPA+ LGA Module
Hardware Guide
Description of the Application Interfaces
Issue 09 (2017-12-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
45
Table 3-16 NC pin
Pin No. Pin Name Pad Type Description Parameter Min.
(V) Typ.
(V) Max.
(V)
2, 3, 16
–27, 33, 37–41,
47, 82
–84, 93–99, 103,
111, 117
–120
NC - Not connected - - - -
3.14 Test Points Design
In the process of debugging when the module is embedded into the integrated
equipment, test points play an important role. Some problems related to the module
can be quickly resolved when test points are properly designed.
1. The test points below must be designed in the customer board:
 JTAG test points: it is the most common method of debugging.

USB test points: USB is the most important communication channel between
module and AP (host). Not only test points should be placed, but also a 0 ohm
series resistor should be placed on USB_D+/USB_D- signal. The resistor can be
welded off when necessary, then the USB of module is cut off from AP and can be
connected to PC to do some analyses.

POWER_ON_OFF, RESIN_N: they are some of the most important signals, test
points should be placed.

UART1: UART1 is used for printing the log information.
 SD signals: SD signals are used for debugging.

VBAT: not only test points should be placed, but also a series magnetic bead
should be placed on VBAT signal. The magnetic bead can be welded off when
necessary, then the power of module is cut off from customer board and can be
connected to external power to do analyses about problems related to power
interference.

VCC_EXT1: to judge whether the module is powered on or not, just test the
VCC_EXT1.

PS_HOLD: the pin is only used for debugging, please reserve this pin as the test
point.
2. The test points below should be placed according to the requirement in the
customer board:
SLEEP_STATUS, GPIO, PCM, USIM, UART1, WAKEUP_IN
and WAKEUP_OUT, except the two cases below:
−
The corresponding signal is not used.
−
The corresponding signal is used, but there is already another place where
this signal can be tested, such as SIM socket pin.