DMA_EARS field descriptions (continued)
Field
Description
3
EDREQ_3
Enable asynchronous DMA request in stop mode for channel 3.
0
Disable asynchronous DMA request for channel 3.
1
Enable asynchronous DMA request for channel 3.
2
EDREQ_2
Enable asynchronous DMA request in stop mode for channel 2.
0
Disable asynchronous DMA request for channel 2.
1
Enable asynchronous DMA request for channel 2.
1
EDREQ_1
Enable asynchronous DMA request in stop mode for channel 1.
0
Disable asynchronous DMA request for channel 1
1
Enable asynchronous DMA request for channel 1.
0
EDREQ_0
Enable asynchronous DMA request in stop mode for channel 0.
0
Disable asynchronous DMA request for channel 0.
1
Enable asynchronous DMA request for channel 0.
22.3.17 Channel n Priority Register (DMA_DCHPRIn)
When fixed-priority channel arbitration is enabled (CR[ERCA] = 0), the contents of these
registers define the unique priorities associated with each channel. The channel priorities
are evaluated by numeric value; for example, 0 is the lowest priority, 1 is the next higher
priority, then 2, 3, etc. Software must program the channel priorities with unique values;
otherwise, a configuration error is reported. The range of the priority value is limited to
the values of 0 through 15.
Address: 4000_8000h base + 100h (1d × i), where i=0d to 15d
Bit
7
6
5
4
3
2
1
0
Read
Write
Reset
0
0
0
0
* Notes:
CHPRI field: See bit field description.
•
DMA_DCHPRIn field descriptions
Field
Description
7
ECP
Enable Channel Preemption.
0
Channel n cannot be suspended by a higher priority channel’s service request.
1
Channel n can be temporarily suspended by the service request of a higher priority channel.
Table continues on the next page...
Chapter 22 Enhanced Direct Memory Access (eDMA)
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
Freescale Semiconductor, Inc.
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