NXP Semiconductors K32 L2A Series, Reference Manual, Page: 468 / 1379

For all error types other than channel priority error, the channel number causing the error
is recorded in the Error Status register (DMAx_ES). If the error source is not removed
before the next activation of the problem channel, the error is detected and recorded
again.
If priority levels are not unique, when any channel requests service, a channel priority
error is reported. The highest channel priority with an active request is selected, but the
lowest numbered channel with that priority is selected by arbitration and executed by the
eDMA engine. The hardware service request handshake signals, error interrupts, and
error reporting is associated with the selected channel.
20.5.3 Arbitration mode considerations
This section discusses arbitration considerations for the eDMA.
20.5.3.1 Fixed channel arbitration
In this mode, the channel service request from the highest priority channel is selected to
execute.
20.5.3.2 Round-robin channel arbitration
Channels are serviced starting with the highest channel number and rotating through to
the lowest channel number without regard to the channel priority levels.
20.5.4 Performing DMA transfers
This section presents examples on how to perform DMA transfers with the eDMA.
20.5.4.1 Single request
To perform a simple transfer of n bytes of data with one activation, set the major loop to
one (TCDn_CITER = TCDn_BITER = 1). The data transfer begins after the channel
service request is acknowledged and the channel is selected to execute. After the transfer
is complete, the TCDn_CSR[DONE] bit is set and an interrupt generates if properly
enabled.
Initialization/application information
K32 L2A Reference Manual, Rev. 2, 01/2020
468 NXP Semiconductors