Rev. 1.00
154
September 11, 2018
Rev. 1.00
155
September 11, 2018
HT45F4050
A/D NFC Flash MCU
HT45F4050
A/D NFC Flash MCU
Bit 3
RIDLE
: Receiver status
0: Data reception is in progress (Data being received)
1: No data reception is in progress (Receiver is idle)
The RIDLE flag is the receiver status flag. When this read only flag is "0", it indicates
that the receiver is between the initial detection of the start bit and the completion of
the stop bit. When the flag is "1", it indicates that the receiver is idle. Between the
completion of the stop bit and the detection of the next start bit, the RIDLE bit is "1"
indicating that the UART receiver is idle and the RX pin stays in logic high condition.
Bit 2
RXIF
: Receive TXR_RXR data register status
0: TXR_RXR data register is empty
1: TXR_RXR data register has available data
The RXIF flag is the receive data register status flag. When this read only flag is "0",
it indicates that the TXR_RXR read data register is empty. When the flag is "1", it
indicates that the TXR_RXR read data register contains new data. When the contents
of the shift register are transferred to the TXR_RXR register, an interrupt is generated
if RIE=1 in the UCR2 register. If one or more errors are detected in the received word,
the appropriate receive-related flags NF, FERR, and/or PERR are set within the same
clock cycle. The RXIF flag will eventually be cleared when the USR register is read
with RXIF set, followed by a read from the TXR_RXR register, and if the TXR_RXR
register has no more new data available.
Bit 1
TIDLE
: Transmission idle
0: Data transmission is in progress (Data being transmitted)
1: No data transmission is in progress (Transmitter is idle)
The TIDLE flag is known as the transmission complete flag. When this read only
flag is "0", it indicates that a transmission is in progress. This flag will be set high
when the TXIF flag is "1" and when there is no transmit data or break character being
transmitted. When TIDLE is equal to "1", the TX pin becomes idle with the pin state
in logic high condition. The TIDLE flag is cleared by reading the USR register with
TIDLE set and then writing to the TXR_RXR register. The flag is not generated when
a data character or a break is queued and ready to be sent.
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 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.