
DMA Registers
11-8
Figure 11–2. DMA Channel Control Register
RWSA
31
27
24 23
21
20
AUX
STATUS
R
STATUS
R
RW-A
START
RW
AUX
START
TCINT
FLAG
19
AUX TCC
18
TCC
17
AUX TCINT
FLAG
R
R
RWSA
RWS
RW-A
14
16
15
RW-A
RW-A
SPLIT
MODE
RWSA
13
WRITE BIT
REV
RWSA
READ BIT
REV
RWS
12
11
10
RWS
AUTOINIT
SYNC
9
6
8
7
5
4
3
2
AUX AUTOINIT
STATIC
RWSA
AUTOINIT
STATIC
RWS
SYNC MODE
AUX TRANSFER
MODE
RWSA
TRANSFER
MODE
RWS
RWSA
RWS
RWSA
RWS
1
0
DMA PRI
RWS
xx
AUX AUTOINIT
SYNC
28
26 25
22
RWS
COM PORT
R
W – Bit may be written.
S
– Bit is shadowed during autoinitialization (no changes take place until autoinitialization is complete.)
A
– Bit is auxiliary for autoinitialization.
xx – Reserved.
DMA Channel 0 only
– Bit may be read.
éé
RW
éééé
éééé
MODE
DMA PRI
Sets DMA coprocessor priority. Defines the arbitration rules to be used when
a DMA channel and the CPU are requesting the same resource. Affects all
DMA coprocessor modes. The rules are listed in Table 11–1
.
TRANSFER
MODE
Defines the transfer mode used by the DMA channel. Affects unified mode
and the primary channel in split mode. The bits are defined in Table 11–2
.
AUX
TRANSFER
MODE
Defines the transfer mode used by the DMA channel. Affects the auxiliary
channel in split mode only. The bits are defined in Table 11–2.
SYNC MODE
Determines the mode of synchronization for performing data transfers,
These bits work differently in unified and split modes. See
Table 11–3 and
Table 11–4 for bit descriptions for unified and split modes.
Note:
If a DMA channel is interrupt driven for both reads and writes, andthe
interrupt for the write comes before the interrupt for the read, the interrupt
for the write is latched by the DMA channel. After the read is complete, the
write can be executed.
AUTOINIT
STATIC
This bit affects unified mode and the primary channel in split mode. It keeps
the auxiliary link pointer constant during autoinitialization from the on-chip
communication ports or other stream-oriented devices (such as first-in first-
out (FIFO) memory buffers).
If bit=0 the link pointer is incremented during
autoinitialization. If bit=1 the link pointer is not ncremented (it is static) dur-
ing autoinitialization.