Rev. 1.10
162
October 23, 2020
Rev. 1.10
163
October 23, 2020
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
Bit 0
TXIF
: Transmit TXR_RXR data register status
0: Character is not transferred to the transmit shift register
1: Character has transferred to the transmit shift register (TXR_RXR data register is
empty)
The TXIF flag is the transmit data register empty flag. When this read only flag is “
0”,
it indicates that the character is not transferred to the transmitter shift register. When
the flag is “
1”, it indicates that the transmitter shift register has received a character
from the TXR_RXR data register. The TXIF flag is cleared to zero by reading the
UART status register (USR) with TXIF set and then writing to the TXR_RXR data
register. Note that when the TXEN bit is set, the TXIF flag bit will also be set since the
transmit data register is not yet full.
• UCR1 Register
The UCR1 register together with the UCR2 register are the two UART control registers that are used
to set the various options for the UART function, such as overall on/off control, parity control, data
transfer bit length etc. Further explanation on each of the bits is given below:
Bit
7
6
5
4
3
2
1
0
Name
UARTEN
BNO
PREN
PRT
STOPS
TXBRK
RX8
TX8
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
W
POR
0
0
0
0
0
0
x
0
“x”: unknown
Bit 7
UARTEN
: UART function enable control
0: Disable UART. TX and RX pins are in a floating state
1: Enable UART. TX and RX pins can function as UART pins
The UARTEN bit is the UART enable bit. When this bit is equal to
“
0”, the UART will
be disabled and the RX pin as well as the TX pin will be in a floating state. When the
bit is equal to
“
1”, the UART will be enabled and the TX and RX pins will function as
defined by the TXEN and RXEN enable control bits.
When the UART is disabled, it will empty the buffer so any character remaining in the
buffer will be discarded. In addition, the value of the baud rate counter will be reset. If
the UART is disabled, all error and status flags will be reset. Also the TXEN, RXEN,
TXBRK, RXIF, OERR, FERR, PERR and NF bits will be cleared to zero, while the
TIDLE, TXIF and RIDLE bits will be set high. Other control bits in UCR1, UCR2 and
BRG registers will remain unaffected. If the UART is active and the UARTEN bit is
cleared to zero, all pending transmissions and receptions will be terminated and the
module will be reset as defined above. When the UART is re-enabled, it will restart in
the same configuration.
Bit 6
BNO
: Number of data transfer bits selection
0: 8-bit data transfer
1: 9-bit data transfer
This bit is used to select the data length format, which can have a choice of either
8-bit or 9-bit format. When this bit is equal to
“
1”, a 9-bit data length format will be
selected. If the bit is equal to
“
0”, then an 8-bit data length format will be selected. If
9-bit data length format is selected, then bits RX8 and TX8 will be used to store the
9th bit of the received and transmitted data respectively.
Bit 5
PREN
: Parity function enable control
0: Parity function is disabled
1: Parity function is enabled
This is the parity enable bit. When this bit is equal to
“
1”, the parity function will be
enabled. If the bit is equal to
“
0”, then the parity function will be disabled.
Bit 4
PRT
: Parity type selection bit
0: Even parity for parity generator
1: Odd parity for parity generator
This bit is the parity type selection bit. When this bit is equal to
“
1”, odd parity type
will be selected. If the bit is equal to
“
0”, then even parity type will be selected.