PXS20RM Datasheet, PDF (421/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Enhanced Direct Memory Access (eDMA)
Table 19-30. TCDn Word 2 (TCDn.nbytes) field descriptions (continued)
Name
dmloe
Description
Destination minor loop offset enable
Value
This flag selects whether the minor loop offset is
applied to the destination address upon minor loop
completion.
nbytes[0:19]
or
mloff[0:19]
nbytes[0:9]
Inner “minor” byte transfer count
or
Minor loop offset
Inner “minor” byte transfer count
0 The minor loop offset is not applied to the daddr.
1 The minor loop offset is applied to the daddr.
If both smloe and dmloe are cleared, this field is part of
the byte transfer count.
If either smloe or dmloe are set, this field represents a
sign-extended offset applied to the source or
destination address to form the next-state value after
the minor loop is completed.
Number of bytes to be transferred in each service
request of the channel.
As a channel is activated, the contents of the
appropriate TCD is loaded into the eDMA engine, and
the appropriate reads and writes performed until the
complete byte transfer count has been transferred. This
is an indivisible operation and cannot be stalled or
halted. Once the minor count is exhausted, the current
values of the saddr and daddr are written back into the
local memory, the major iteration count is decremented
and restored to the local memory. If the major iteration
count is completed, additional processing is performed.
This field is extended to 30 bits when both smloe and
dmloe are cleared (disabled).
Figure 19-22 and Table 19-31 define word 3 of the TCDn structure, the slast field.
Register address: DMA_Offset + 0x1000 + (32 x n) + 0x0c
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R
slast[0:15]
W
RESET: -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R
slast[16:31]
W
RESET: -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
= Unimplemented
Figure 19-22. TCDn Word 3 (TCDn.slast) Field
Freescale Semiconductor
PXS20 Microcontroller Reference Manual, Rev. 1
19-25