DMA_TCDn_NBYTES_MLOFFNO field descriptions (continued)
Field Description
0 The minor loop offset is not applied to the DADDR
1 The minor loop offset is applied to the DADDR
NBYTES Minor Byte Transfer Count
Number of bytes to be transferred in each service request of the channel.
As a channel activates, the appropriate TCD contents load into the eDMA engine, and the appropriate
reads and writes perform until the minor byte transfer count has transferred. This is an indivisible operation
and cannot be halted. It can, however, be stalled by using the bandwidth control field, or via preemption.
After the minor count is exhausted, the SADDR and DADDR values are written back into the TCD
memory, the major iteration count is decremented and restored to the TCD memory. If the major iteration
count is completed, additional processing is performed.
22.3.27 TCD Signed Minor Loop Offset (Minor Loop Mapping and
Offset Enabled) (DMA_TCDn_NBYTES_MLOFFYES)
One of three registers (this register, TCD_NBYTES_MLNO, or
TCD_NBYTES_MLOFFNO), defines the number of bytes to transfer per request. Which
register to use depends on whether minor loop mapping is disabled, enabled but not used
for this channel, or enabled and used.
TCD word 2 is defined as follows if:
• Minor loop mapping is enabled (CR[EMLM] = 1) and
• Minor loop offset is enabled (SMLOE or DMLOE = 1)
If minor loop mapping is enabled and SMLOE and DMLOE are cleared, then refer to the
TCD_NBYTES_MLOFFNO register description. If minor loop mapping is disabled, then
refer to the TCD_NBYTES_MLNO register description.
Address:
4000_8000h base + 1008h offset + (32d × i), where i=0d to 15d
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
R
SMLOE
DMLOE
MLOFF
W
Reset
x* x* x* x* x* x* x* x* x* x* x* x* x* x* x* x*
Bit
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R
MLOFF NBYTES
W
Reset
x* x* x* x* x* x* x* x* x* x* x* x* x* x* x* x*
* Notes:
Chapter 22 Enhanced Direct Memory Access (eDMA)
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
NXP Semiconductors 473
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