Datasheet

Table Of Contents
34.6.4 DMA, Interrupts and Events
Table 34-4. Module Request for SERCOM USART
Condition Request
DMA Interrupt Event
Data Register Empty (DRE) Yes
(request cleared when data is written)
Yes NA
Receive Complete (RXC) Yes
(request cleared when data is read)
Yes
Transmit Complete (TXC) NA Yes
Receive Start (RXS) NA Yes
Clear to Send Input Change (CTSIC) NA Yes
Receive Break (RXBRK) NA Yes
Error (ERROR) NA Yes
34.6.4.1 DMA Operation
The USART generates the following DMA requests:
Data received (RX): The request is set when data is available in the receive FIFO. The request is
cleared when DATA is read.
Data transmit (TX): The request is set when the transmit buffer (TX DATA) is empty. The request is
cleared when DATA is written.
34.6.4.2 Interrupts
The USART has the following interrupt sources. These are asynchronous interrupts, and can wake-up the
device from any Sleep mode:
Data Register Empty (DRE)
Receive Complete (RXC)
Transmit Complete (TXC)
Receive Start (RXS)
Clear to Send Input Change (CTSIC)
Received Break (RXBRK)
Error (ERROR)
Each interrupt source has its own Interrupt flag. The Interrupt flag in the Interrupt Flag Status and Clear
register (INTFLAG) will be set when the Interrupt condition is met. Each interrupt can be individually
enabled by writing '1' to the corresponding bit in the Interrupt Enable Set register (INTENSET), and
disabled by writing '1' to the corresponding bit in the Interrupt Enable Clear register (INTENCLR).
An interrupt request is generated when the Interrupt flag is set and if the corresponding interrupt is
enabled. The interrupt request remains active until either the Interrupt flag is cleared, the interrupt is
disabled, or the USART is reset. For details on clearing Interrupt flags, refer to the INTFLAG register
description.
The value of INTFLAG indicates which interrupt is executed. Note that interrupts must be globally
enabled for interrupt requests. Refer to Nested Vector Interrupt Controller for details.
SAM D5x/E5x Family Data Sheet
SERCOM USART - SERCOM Synchronous and Asyn...
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Datasheet
DS60001507E-page 940