GD32W51x User Manual
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When the channel is disabled because of register access error before the end of the
transfer, the current memory and peripheral is completed and the contents of the FIFO
are entirely written into the memory in peripheral-to-memory or memory-to-memory
mode.
When the full transfer finish flag is asserted and the enabled bit for the full transfer finish
interrupt is set, an interrupt is generated.
The half transfer finish flag is asserted, only when DMA is the transfer flow controller and half
of the CNT bits are transferred. If peripheral is the transfer flow controller, DMA does not know
when half of data items has been transferred and the half transfer finish flag will stay zero.
When the half transfer finish flag is asserted and the enabled bit for the half transfer finish
interrupt is set, an interrupt is generated.
12.5.2.
Exception
Two exception events are supported, including single-data mode exception and FIFO
exception. These exceptions have no effect on the DMA transmission.
Single-data mode exception
This exception can be detected only when the single-data mode is enabled and the transfer
mode is peripheral-to-memory. When a peripheral request is valid and the FIFO is not empty,
there are two or more data items stored in the FIFO after responding the peripheral request,
which could be a problem for the subsequent processing of the data.
When the single-data mode exception is asserted and the enabled bit for the single-data
mode exception interrupt is set, an interrupt is generated.
FIFO exception
When a FIFO underrun or a FIFO overrun condition occurs, the FIFO exception is asserted.
This exception can be detected only when the transmission is between peripheral and
memory.
In peripheral-to-memory mode, when a peripheral request is valid and there is not enough
space in the FIFO for the single or burst peripheral transfer, a FIFO overrun condition is
detected. This peripheral request is not responded until the FIFO space is enough, and the
accuracy of the data transmission will not be destroyed.
In memory-to-peripheral mode, when a peripheral request is valid and there is not enough
data in the FIFO for the single or burst peripheral, a FIFO underrun condition is detected. This
peripheral request is not responded until the data number in the FIFO is enough, and the
accuracy of the data transmission will not be destroyed.
When the FIFO exception is asserted and the enabled bit for the FIFO error and exception
interrupt is set, an interrupt is generated.