ADSP-214xx SHARC Processor Hardware Reference 3-103
External Port
Standard DMA
This DMA type resembles the traditional DMA type to initialize the dif-
ferent internal and external parameters (index, modify and count) registers
and configuration of the DMA control registers.
Note that the
ECEP parameter register (read only) is a copy of the ICEP reg-
ister. If ICEP is written, the ECEP register is updated automatically
(Figure 3-21).
Circular Buffered DMA
Circular buffered DMA (Figure 3-22, Figure 3-23) resembles the tradi-
tional core DAG circular buffered mode by using registers for circular
buffering. In this mode the DMA needs two additional registers (base and
length) to support reads and writes to a circular buffer.
Figure 3-21. Standard Write
20
19
18
3
2
1
1
2
3
4
DESTINATION INDEX
SOURCE INDEX
DESTINATION BUFFER
SOURCE BUFFER
17
20
19
18