U8655
Maintenance Manual
9 Principles and Failure Analysis
Issue 1.0 (2012-02-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
33
H
H
LO Power
H: 1.3–1.8 V. L: < 0.5 V.
9.3.2 GPS
The GPS channel consists of filter U4102, filter U4103 and LNA U4101. GPS signals are sent
to the RTR6285A's input interface after going through the filters and LNA. The following
figure shows the circuit.
9.3.3 Wi-Fi/Bluetooth/FM Module
The U8655N uses a Wi-Fi/Bluetooth/FM 3-in-1 module (Broadcom's BCM4330).
The Bluetooth and Wi-Fi functions share one antenna and one SP3T RF switch.
The MSM7225A provides PCM and UART interfaces that are directly connected with the
Bluetooth module's PCM and UART signal output. The following table describes the signals'
definitions.
MSM7225A Signal
Definition
GPIO_44
UART1_CTS_N
The "ready to receive" signal from the
host (the MSM7225A) to the slave (the
BCM4330).
GPIO_43
UART1_RFR_N
The "clear to send" signal sent from the
slave to the host.
GPIO_46
UART1_TX
Transmission signal
GPIO_45
UART1_RX
Reception signal
GPIO_69
AUX_PCM_DIN
PCM input
GPIO_68
AUX_PCM_DOUT
PCM output
GPIO_70
AUX_PCM_SYNC
PCM synchronization
GPIO_71
AUX_PCM_CLK
PCM clock
GPIO_107
MSM_WAKES_BT
Waking up the host
GPIO_83
BT_WAKES_MSM
Waking up the Bluetooth
