Signal Name
I/O
Function
Notes
Clocking
SYS_CLK
I
Cellular engine RF clock
(26.0 MHz)
SLEEP_CLK
I
Cellular engine sleep
clock (32.768kHz)
Bluetooth Control
BT_RESETX
I
Bluetooth ASIC reset
CLK_REQ
O
Signal from Bluetooth
ASIC to indicate that
SYSCLK is required
UART_WAKEUP
O
Signal from Bluetooth
ASIC to wakeup host
engine
BT_WAKEUP
I
Signal from host engine
to wakeup Bluetooth
ASIC
Bluetooth Communication
UART_RX
I
UART interface to/from
host engine
UART_CTS
I
UART_TX
O
UART_RTS
O
Bluetooth Audio Interface
PCM_IN
I
PCM interface to/from
host engine
PCM_OUT
O
PCM_SYNC
I
PCM_CLK
I
Power
VIO
P
Cellular engine I/O
supply
VBAT
P
Phone battery power
Alternative connection
to 1.8V supply could be
used
Component placement
The Bluetooth ASIC, is checked when troubleshooting (if supported).
The placement of Bluetooth and test probe points is shown below.
The Bluetooth antenna is product specific (PWB track, SMD antenna, clip on antenna, or antenna integrated
into phone covers) and is typically located near the side of the PWB.
RM-761; RM-799; RM-800
RF Troubleshooting
Issue 1
COMPANY CONFIDENTIAL
Page 4 – 51
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