Table 3-14. Bluetooth Host Processor Uart I/O - Motorola APX 1000 Detailed Service Manual

Theory of Operation
: Bluetooth
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.
Signal Name
USART0–RXD
USART0–TXD
USART0–RTS
USART0–CTS
USART1–RXD
USART1–TXD
USART1–CLK
USART2–RXD
USART2–TXD

Table 3-14. Bluetooth Host Processor UART I/O

Pad Name GPIO
PA00 0
PA01 1
PA03 3
PA04 4
PA05 5
PA06 6
PA07 7
PB29 61
PB30 62
MUX Keypad Board
Function Schematic Name
A BT_UART_TX_3.3V
A BT_UART_RX_3.3V
A BT_UART_CTS_3.3V
A BT_UART_RTS_3.3V
A USART1_RX
A USART1_TX
A USART1_CLK
A AVR_USART2_RX
A AVR_USART2_TX
3-63
I/O
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O
O
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I
O
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O