![NXP Semiconductors MKL27Z128VFM4 Reference Manual Download Page 316](http://html1.mh-extra.com/html/nxp-semiconductors/mkl27z128vfm4/mkl27z128vfm4_reference-manual_1721847316.webp)
DMA_DCRn field descriptions (continued)
Field
Description
Determines whether an interrupt is generated by completing a transfer or by the occurrence of an error
condition.
0
No interrupt is generated.
1
Interrupt signal is enabled.
30
ERQ
Enable Peripheral Request
CAUTION: Be careful: a collision can occur between START and D_REQ when ERQ is 1.
0
Peripheral request is ignored.
1
Enables peripheral request to initiate transfer. A software-initiated request (setting START) is always
enabled.
29
CS
Cycle Steal
0
DMA continuously makes read/write transfers until the BCR decrements to 0.
1
Forces a single read/write transfer per request.
28
AA
Auto-align
AA and SIZE bits determine whether the source or destination is auto-aligned; that is, transfers are
optimized based on the address and size.
0
Auto-align disabled
1
If SSIZE indicates a transfer no smaller than DSIZE, source accesses are auto-aligned; otherwise,
destination accesses are auto-aligned. Source alignment takes precedence over destination
alignment. If auto-alignment is enabled, the appropriate address register increments, regardless of
DINC or SINC.
27–25
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
24
Reserved
This field is reserved.
CAUTION: Must be written as zero; otherwise, undefined behavior results.
23
EADREQ
Enable asynchronous DMA requests
Enables the channel to support asynchronous DREQs while the MCU is in Stop mode.
0
Disabled
1
Enabled
22
SINC
Source Increment
Controls whether the source address increments after each successful transfer.
0
No change to SAR after a successful transfer.
1
The SAR increments by 1, 2, 4 as determined by the transfer size.
21–20
SSIZE
Source Size
Determines the data size of the source bus cycle for the DMA controller.
00
32-bit
01
8-bit
Table continues on the next page...
Memory Map/Register Definition
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
316
Freescale Semiconductor, Inc.