TC1796
System Units (Vol. 1 of 2)
Direct Memory Access Controller
User’s Manual
12-76
V2.0, 2007-07
DMA, V2.0
12.2.4
Channel Control/Status Registers
The Channel Control Register for DMA channel mx contains its configuration and its
control bits and bit fields.
DMA_CHCR0x (x = 0-7)
DMA Channel 0x Control Register
(x*20
H
+84
H
)
Reset Value: 0000 0000
H
DMA_CHCR1x (x = 0-7)
DMA Channel 1x Control Register
(x*20
H
+184
H
)
Reset Value: 0000 0000
H
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
0
DMA
PRIO
0
CH
PRIO
0
PATSEL
0
CHDW
CH
MO
DE
RRO
AT
BLKM
r
rw
r
rw
r
rw
r
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PRSEL
0
TREL
rw
r
rw
Field
Bits
Type Description
TREL
[8:0]
rw
Transfer Reload Value
This bit field contains the number of DMA transfers for s
DMA transaction of DMA channel mx. This 9-bit transfer
count value is loaded into CHSRmx.TCOUNT at the
start of a DMA transaction (when TRSR.CHmx
becomes set and CHSRmx.TCOUNT = 0). TREL can
be written during a running DMA transaction because
TCOUNT will be updated (decremented) during the
DMA transaction.
If TREL = 0 or if TREL = 1, TCOUNT will be loaded with
1 when a new transaction is started (at least one DMA
transfer must be executed per DMA transaction).