Tcd Signed Source Address Offset (Dma_Tcdn_Soff) - STMicroelectronics SPC572L series Reference Manual

Enhanced Direct Memory Access (eDMA)
Field
Source address modulo.
0 Source address modulo feature is disabled
≠0 This value defines a specific address range specified to be the value after SADDR + SOFF
calculation is performed on the original register value. Setting this field provides the ability to
implement a circular data queue easily. For data queues requiring power-of-2 size bytes, the
16–20
queue should start at a 0-modulo-size address and the SMOD field should be set to the
SMOD
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.
Source data transfer size
Using a reserved encoding causes a configuration error.
000 8-bit
001 16-bit
21–23
010 32-bit
SSIZE
011 Reserved
100 16-byte
101 Reserved
110 Reserved
111 Reserved
24–28 Destination address modulo
DMOD See the SMOD definition
29–31 Destination data transfer size
DSIZE See the SSIZE definition
19.3.20

TCD Signed Source Address Offset (DMA_TCDn_SOFF)

See TCD Signed Source Address Offset register figure and DMA_TCDn_SOFF field
descriptions table as follows.
Address: FC0A_0000h base + 1006h offset + (32d × n), where n = 0d to 63d
0 1
R
W
(1)
Reset x x
Figure 138. TCD Signed Source Address Offset (DMA_TCDn_SOFF)
1. x = Undefined at reset.
Field
Source address signed offset
16–31
Sign-extended offset applied to the current source address to form the next-state value as each
SOFF
source read is completed.
418/2058
Table 183. DMA_TCDn_ATTR field descriptions
2 3 4 5
x x x x
Table 184. DMA_TCDn_SOFF field descriptions
DocID027809 Rev 4
Description
6 7 8 9
SOFF
x x x x
Description
Access: User read/write
10 11 12 13
x x x x
RM0400
14 15
x x