Enhanced Direct Memory Access (eDMA) RM0046
402/936 Doc ID 16912 Rev 5
37–39
0x4 [5:7]
SSIZE
[0:2]
Source data transfer size.
000 8-bit
001 16-bit
010 32-bit
011 64-bit
100 32-bit
101 32-byte burst (64-bit x 4)
110 Reserved
111 Reserved
The attempted specification of a ‘reserved’ encoding causes a configuration error.
40–44
0x4 [8:12]
DMOD
[0:4]
Destination address modulo. Refer to the SMOD[0:5] definition.
45–47
0x4 [13:15]
DSIZE
[0:2]
Destination data transfer size. Refer to the SSIZE[0:2] definition.
48–63
0x4 [16:31]
SOFF
[0:15]
Source address signed offset. Sign-extended offset applied to the current source
address to form the next-state value as each source read is completed.
64–95
0x8 [0:31]
NBYTES
[0:31]
Inner “minor” byte transfer count. 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.
The NBYTES value of 0x0000_0000 is interpreted as 0x1_0000_0000, thus specifying a
four GB transfer.
96–127
0xC [0:31]
SLAST
[0:31]
Last source address adjustment. Adjustment value added to the source address at
the completion of the outer major iteration count. This value can be applied to
“restore” the source address to the initial value, or adjust the address to reference
the next data structure.
128–159
0x10 [0:31]
DADDR
[0:31]
Destination address. Memory address pointing to the destination data.
160
0x14 [0]
CITER.E_LINK
Enable channel-to-channel linking on minor loop completion. As the channel
completes the inner minor loop, this flag enables the linking to another channel,
defined by CITER.LINKCH[0:5]. The link target channel initiates a channel service
request via an internal mechanism that sets the TCD.START bit of the specified
channel. If channel linking is disabled, the CITER value is extended to 15 bits in
place of a link channel number. If the major loop is exhausted, this link mechanism
is suppressed in favor of the MAJOR.E_LINK channel linking.
0 The channel-to-channel linking is disabled.
1 The channel-to-channel linking is enabled.
This bit must be equal to the BITER.E_LINK bit otherwise a configuration error is
reported.
Table 193. TCDn field descriptions (continued)
Bits
Word Offset
[n:n]
Field Name Description
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