Rev. 1.10
160
October 23, 2020
Rev. 1.10
161
October 23, 2020
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
UART Interface
The device contains an integrated full-duplex asynchronous serial communications UART interface
that enables communication with external devices that contain a serial interface. The UART function
has many features and can transmit and receive data serially by transferring a frame of data with
eight or nine data bits per transmission as well as being able to detect errors when the data is
overwritten or incorrectly framed. The UART function possesses its own internal interrupt which
can be used to indicate when a reception occurs or when a transmission terminates.
The integrated UART function contains the following features:
• Full-duplex, asynchronous communication
• 8 or 9 bits character length
• Even, odd or no parity options
• One or two stop bits
• Baud rate generator with 8-bit prescaler
• Parity, framing, noise and overrun error detection
• Support for interrupt on address detect (last character bit=1)
• Separately enabled transmitter and receiver
•
2-byte Deep FIFO Receive Data Buffer
• RX pin wake-up function
• Transmit and receive interrupts
• Interrupts can be triggered by the following conditions:
♦
Transmitter Empty
♦
Transmitter Idle
♦
Receiver Full
♦
Receiver Overrun
♦
Address Mode Detect
MSB
LSB
…………………………
Transmitter Shift Register (TSR)
MSB
LSB
…………………………
Receiver Shift Register (RSR)
TX Pin
RX Pin
Baud Rate
Generator
TXR_RXR Register
TXR_RXR Register
Data to be transmitted
Data received
Buffer
f
H
MCU Data Bus
UART Data Transfer Block Diagram
UART External Pins
To communicate with an external serial interface, the internal UART has two external pins known as
TX and RX. The TX and RX pins are the UART transmitter and receiver pins respectively. The TX
and RX pin function should first be selected by the pin-shared function selection register before the
UART function is used. Along with the UARTEN bit, the TXEN and RXEN bits, if set, will setup
these pins to their respective TX output and RX input conditions and disable any pull-high resistor
option which may exist on the TX and RX pins. When the TX or RX pin function is disabled by
clearing the UARTEN, TXEN or RXEN bit, the TX or RX pin will be set to a floating state. At this
time whether the internal pull-high resistor is connected to the TX or RX pin or not is determined by
the corresponding I/O pull-high function control bit.