AT32WB415
Series Reference Manual
2022.04.13
Page 142
Ver 2.00
When noise is detected in a data frame:
The NERR bit is set at the same time as the RDBF bit
The invalid data is transferred from the receive shift register to the receive data buffer.
No interrupt is generated in non-DMA mode. However, since the NERR bit is set at the same
time as the RDBF bit, the RDBF bit will generae an interrupt. In DMA mode, an interrupt will be
issued if the ERRIEN is set.
The NERR bit is cleared by read access to USART_STS register followed by the USART_DT read
operation.
12.9 Interrupt requests
USART interrupt generator serves as a control center of USART interrupts. It is used to monitor the
interrupt source inside the USART in real time and the generation of interrupts according to the
programmed interrupt control bits. Table 12-4 shows the USART interrupt source and interrupt enable
control bit. An interrupt will be generated over an event when the corresponding interrupt enable bit is
set.
Table 12-3
USART interrupt request
Interrupt event
Event flag
Enable bit
Transmit data register empty
TDBE
TDBEIEN
CTS flag
CTSCF
CTSCFIEN
Transmit data complete
TDC
TDCIEN
Receive data buffer full
RDBF
RDBFIEN
Receiver overflow error
ROERR
Idle flag
IDLEF
IDLEIEN
Parity error
PERR
PERRIEN
Break frame flag
BFF
BFIEN
Noise error, overflow error or framing error
NERR or ROERR or FERR
ERRIEN
(
1
)
Figure 12-2 USART interrupt map diagram
USART
interrupt
TDBE
TDBEIEN
TDC
TDCIEN
CTSCF
CTSCFIEN
IDLEF
IDLEIEN
RDBFIEN
ROERR
RDBFIEN
RDBF
PERR
PERRIEN
BFF
BFIEN
FERR
NERR
ROERR
ERRIEN
DMAREN
12.10 I/O pin control
The following five interfaces are used for USART communication.
RX: Serial data input.
TX: Serial data output. In single-wire half-duplex and Smartcard mode, the TX pin is used as an I/O for
data transmission and reception.
CK: Transmitter clock output. The output CLK phase, polarity and frequency can be programmable.
CTS: Transmitter input. Send enable signal in hardware flow control mode.
RTS: Receiver output. Send request signal in hardware flow control mode.