Holtek HT32F50231 User Manual page 458

32-Bit Arm ® Cortex ® -M0+ MCU
HT32F50231/HT32F50241
Bits Field
[6] RXTOF
[5] RXDR
[4] BII
[3] FEI
[2] PEI
[1] OEI
[0] RXDNE
Rev. 1.00
Descriptions
Receive FIFO Time-Out Flag
0: RX FIFO Time-Out does not occur
1: RX FIFO Time-Out occurs
The RXTOF bit will be set if the receive FIFO is not empty and no activities have
occurred in the receive FIFO during the time-out duration specified by the RXTOC
field. Writing 1 to this bit clears the flag.
Receive FIFO Ready Flag
0: RX FIFO level is less than threshold
1: RX FIFO level is higher than threshold
The RXDR bit will be set when the FIFO received data amount reaches the specified
threshold level which is set by the RXTL field in the USRFCR register. This bit will
be cleared when the data is read from the USRDR register and the RX FIFO level is
less than threshold setting.
Break Interrupt Indicator
This bit will be set to 1 whenever the received data input is held in the "spacing state"
(logic 0) for longer than a full word transmission time, which is the total time of "start
bit" + "data bits" + "parity" + "stop bits" duration. Writing 1 to this bit clears the flag.
Framing Error Indicator
This bit will be set to 1 whenever the received character does not have a valid "stop
bit", which means the stop bit following the last data bit or parity bit is detected as a
logic 0. Writing 1 to this bit clears the flag.
Parity Error Indicator
This bit will be set to 1 whenever the received character does not have a valid "parity
bit". Writing 1 to this bit clears the flag.
Overrun Error Indicator
An overrun error will occur only after the RX FIFO is full and when the next character
has been completely received in the RX shift register. The character in the shift
register will be overwritten if a new character is received in the RX shift register after
an overrun event occurs, but the data in the RX FIFO will not be overwritten. The OEI
bit is used to indicate the overrun event as soon as it happens. Writing 1 to this bit
clears the flag.
RX FIFO Data Not Empty
0: RX FIFO is empty
1: RX FIFO contains at least 1 received data word
458 of 486 July 31, 2018