Quick DMA (QDMA)
6-39
EDMA Controller
Figure 6–19. QDMA Pseudo Registers
31 0
QDMA_S_OPT
QDMA options
0200 0020h
31 0
QDMA_S_SRC
SRC address
0200 0024h
31 16
15 0
QDMA_S_CNT
Arrary/frame count
Element count
0200 0028h
31 0
QDMA_S_DST
DST address
0200 002Ch
31 16
15 0
QDMA_S_IDX
Arrary/frame index
Element index
0200 0030h
The QDMA options register shown in Figure 6–20 is similar to the options
parameter in the EDMA parameter RAM, which is shown in Figure 6–8 and
described in Table 6–3. All fields in the registers function identically to the
corresponding EDMA transfer parameters. Refer to section 6.6 and the
corresponding sections for details. However, the QDMA does not support
parameter updates (e.g. element count reload), or transfer event linking. Since
the QDMA does not support transfer event linking, bit 1 of the QDMA_OPT
register is reserved, as opposed to the LINK bit-field in the EDMA options
parameter.
Figure 6–20. QDMA Options Register (QDMA_OPT, QDMA_S_OPT)
31 29
28 27
26
25 24
23
22 21
20
19 16
15 1
0
PRI
ESIZE
2DS
SUM
2DD
DUM
TCINT
TCC
Reserved
FS
RW, +0
RW, +0
RW, +0
RW, +0
RW, +0
RW, +0
RW, +0
RW, +0
R,+0
RW,+0
Although the QDMA mechanism does not support event linking, it supports
completion interrupts, as well as QDMA chaining with EDMA events. The
QDMA_OPT and the QDMA_S_OPT registers include the same TCINT and
TCC fields as the EDMA options parameter. QDMA completion interrupts are
enabled and set in the same way as EDMA completion interrupts. To set a
QDMA completion interrupt, the user needs to set TCINT to ’1’ and program
the transfer completion code field (TCC) to specify the interrupt desired. The