NXP Semiconductors MPC5644A, Reference Manual, Page: 167 / 1735

Enhanced Direct Memory Access Controller (eDMA)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 167
Table 8-20. TCDn field descriptions
Bits /
Word offset
[n:n]
Name Description
0–31 /
0x0 [0:31]
SADDR
[0:31]
Source address
Memory address pointing to the source data.
Word 0x0, bits 0–31.
32–36 /
0x4 [0:4]
SMOD
[0:4]
Source address modulo
0
Source address modulo feature is disabled.
non-0 This value defines a specific address range that is specified to be the
value after SADDR + SOFF calculation is performed or the original
register value. The setting of this field provides the ability to easily
implement a circular data queue. For data queues requiring power-of-2
size bytes, the queue should start at a 0-modulo-size address and the
SMOD field should be set to the appropriate value for the queue, freezing
the desired number of upper address bits. The value programmed into
this field specifies the number of lower address bits that are allowed to
change. For this circular queue application, the SOFF is typically set to
the transfer size to implement post-increment addressing with the SMOD
function constraining the addresses to a 0-modulo-size range.
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 Reserved
101 32-byte (64-bit, 4 beat, WRAP4 burst)
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
See the SMOD[0:5] definition.
45–47 /
0x4 [13:15]
DSIZE
[0:2]
Destination data transfer size
See 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
0x8 [0]
SMLOE
0
Source minor loop offset enable
This flag selects whether the minor loop offset is applied to the source address
upon minor loop completion.
0 The minor loop offset is not applied to the saddr.
1 The minor loop offset is applied to the saddr.
65
0x8 [1]
DMLOE
1
Destination minor loop offset enable
This flag selects whether the minor loop offset is applied to the destination
address upon minor loop completion.
0 The minor loop offset is not applied to the daddr.
1 The minor loop offset is applied to the daddr.