Theory of Operation
: Bluetooth
3-63
3.5.2
Bluetooth Clocks
The Bluetooth IC requires a 26 MHz TCXO (Y1304, TCXO_CLK) for the core and a 32.768 kHz
(U6101 pin E2 on Main Board, RTC_CLK) slow clock for the USART. This is the same clock used for
the GPS portion of the BT/GPS combination IC.
The host processor IC requires a 12 MHz crystal oscillator (Y2475) clock. The LF receiver IC
requires a 32.768 kHz (U6101 pin E2 on Main Board, RTC_CLK) clock.
3.5.3
Bluetooth I/Os
The communication between the Bluetooth IC and the host controller is by a four-wire HCI USART0
bus (RX, TX, CTS, RTS). The Bluetooth IC receives a firmware update over the USART0 each time
it is powered on. The LF receiver IC transmits its data over the USART1. USART2 is used for
displaying debugging messages.
Table 3-14. Bluetooth Host Processor UART I/O
Signal Name
Pad Name
GPIO
MUX
Function
Keypad Board
Schematic Name
I/O
USART0–RXD
PA00
0
A
BT_UART_TX_3.3V
I
USART0–TXD
PA01
1
A
BT_UART_RX_3.3V
O
USART0–RTS
PA03
3
A
BT_UART_CTS_3.3V
O
USART0–CTS
PA04
4
A
BT_UART_RTS_3.3V
I
USART1–RXD
PA05
5
A
USART1_RX
I
USART1–TXD
PA06
6
A
USART1_TX
O
USART1–CLK
PA07
7
A
USART1_CLK
I
USART2–RXD
PB29
61
A
AVR_USART2_RX
I
USART2–TXD
PB30
62
A
AVR_USART2_TX
O
Summary of Contents for APX 2000
Page 1: ...APXTM TWO WAY RADIOS APX 1000 APX 2000 APX 4000 APX 4000Li DETAILED SERVICE MANUAL ...
Page 4: ......
Page 6: ...iv Document History Notes ...
Page 8: ...Notes vi Commercial Warranty ...
Page 10: ...Notes ...
Page 22: ...xiv List of Figures Notes ...
Page 226: ...6 64 Troubleshooting Waveforms LF CW on Spectrum Analyzer Notes ...
Page 688: ...Index 4 Index Notes ...
Page 690: ...ii Notes ...
Page 700: ...xvi List of Figures Notes ...
Page 806: ...5 50 Troubleshooting Charts PA Failure Notes ...
Page 1008: ...8 178 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF2 84012621001 Notes ...
Page 1062: ...8 234 Schematics Boards Overlays and Parts Lists Keypad Board M2 and M3 PC000261A01 Notes ...
Page 1064: ...ii Notes ...
Page 1068: ...Notes A 4 EMEA Warranty Service and Technical Support Further Assistance From Motorola ...
Page 1090: ...Glossary 10 Glossary Notes ...
Page 1094: ...Index 4 Index Notes ...
Page 1095: ......