Freescale Semiconductor MCF54455 Reference Manual page 433

Enhanced Direct Memory Access (eDMA)
Field
31–0 Source address. Memory address pointing to the source data.
SADDR
Address: 0xFC04_5004 + (0x20 n) (TCDn_ATTR)
15 14 13
R
SMOD
W
Reset — — —
Field
15–11 Source address modulo.
SMOD 0 Source address modulo feature is disabled.
non-0 This value defines a specific address range 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
implement a circular data queue easily. 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 allowed to change. For a 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.
10–8 Source data transfer size.
SSIZE 000 8-bit
001 16-bit
010 32-bit
100 16-byte
Else Reserved
The attempted use of a Reserved encoding causes a configuration error.
7–3 Destination address modulo. See the SMOD definition.
DMOD
2–0 Destination data transfer size. See the SSIZE definition.
DSIZE
Address: 0xFC04_5006 + (0x20 n) (TCDn_SOFF)
15 14 13
R
W
Reset — — —
Figure 19-20. TCDn Signed Source Address Offset (TCDn_SOFF)
19-18
Table 19-20. TCDn_SADDR Field Descriptions
12 11 10 9
SSIZE
— — — —
Figure 19-19. TCDn Transfer Attributes (TCDn_ATTR)
Table 19-21. TCDn_ATTR Field Descriptions
12 11 10 9
— — — —
Description
8 7 6 5
DMOD
— — — —
Description
8 7 6 5
SOFF
— — — —
Access: User read/write
4 3 2 1
DSIZE
— — — —
Access: User read/write
4 3 2 1
— — — —
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