EFM32WG Datasheet, PDF (469/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

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• Transmit buffer has room for RIGHT I2S data. Only used in I2S mode.
Even though there are two sources for write requests to the DMA, only one should be used at a time,
since the requests from both sources are cleared even though only one of the requests are used.
In some cases, it may be sensible to temporarily stop DMA access to the USART when an error such
as a framing error has occurred. This is enabled by setting ERRSDMA in USARTn_CTRL.
17.3.7 Transmission Delay
By configuring TXDELAY in USARTn_CTRL, the transmitter can be forced to wait a number of bit-
periods from it is ready to transmit data, to it actually transmits the data. This delay is only applied to the
first frame transmitted after the transmitter has been idle. When transmitting frames back-to-back the
delay is not introduced between the transmitted frames.
This is useful on half duplex buses, because the receiver always returns received frames to software
during the first stop-bit. The bus may still be driven for up to 3 baud periods, depending on the current
frame format. Using the transmission delay, a transmission can be started when a frame is received,
and it is possible to make sure that the transmitter does not begin driving the output before the frame
on the bus is completely transmitted.
TXDELAY in USARTn_CTRL only applies to asynchronous transmission.
17.3.8 Interrupts
The interrupts generated by the USART are combined into two interrupt vectors. Interrupts related to
reception are assigned to one interrupt vector, and interrupts related to transmission are assigned to
the other. Separating the interrupts in this way allows different priorities to be set for transmission and
reception interrupts.
The transmission interrupt vector groups the transmission-related interrupts generated by the following
interrupt flags:
• TXC
• TXBL
• TXOF
• CCF
The reception interrupt on the other hand groups the reception-related interrupts, triggered by the
following interrupt flags:
• RXDATAV
• RXFULL
• RXOF
• RXUF
• PERR
• FERR
• MPAF
• SSM
If USART interrupts are enabled, an interrupt will be made if one or more of the interrupt flags in
USART_IF and their corresponding bits in USART_IEN are set.
17.3.9 IrDA Modulator/Demodulator
The IrDA modulator on USART0 implements the physical layer of the IrDA specification, which is
necessary for communication over IrDA. The modulator takes the signal output from the USART module,
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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