Figure 3-40. Bluetooth Low-Frequency Circuit Block Diagram; Figure 3-41. Bluetooth Low-Frequency Pairing Data Path - Motorola APX 3000 Detailed Service Manual

Theory of Operation
: Bluetooth
To verify the Bluetooth transmitter is operational, an RCMP command can be sent to transmit a
constant carrier waveform on a Bluetooth frequency. To verify the LF transmit feature is operational,
an RCMP command can be sent to transmit a constant carrier waveform at 125 kHz. There are
similar RCMP commands for verifying BT/LF RSSI when a CW BT/LF signal is applied near the
antennas of the BT/LF circuitry.
The Low-Frequency block diagram below shows the main connections:
ATMEL AVR32
AT32UC3A0512
NFC_UART_MAN_CLK
LF TX
UART
125 KHz Clock
UART_TX_Data
Micro-
Processor
SPI0_SCK
SPI0_MOSI
SPI0_MISO
NFC_CS
NFC_INT
NFC_UART_RX
NFC_UART_TX
TC1_OCA

Figure 3-40. Bluetooth Low-Frequency Circuit Block Diagram

SPI
ANTENNA COIL

Figure 3-41. Bluetooth Low-Frequency Pairing Data Path

SCL
LF RX
XIN
SDI
SDO
CS
Low Frequency
Receiver
AS3930
WAKE
LF1P
LFN
DAT
CL_DAT
+
32 KHz
32768 Hz
Clock
LF Coil
SPI
UART
ANT_IN
LF Device
CLK_IN
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