319
DMA Controller (DMAC)
Chapter 8
Preliminary User’s Manual U17566EE1V2UM00
8.3.5
DCHCn - DMA channel control registers
These 8-bit registers are used to control the DMA transfer operating mode for
DMA channel n.
These registers can be read/written in 8-bit or 1-bit units. (However, bit 7 is
read only and bits 2 and 1 are write only. If bits 2 and 1 are read, the read
value is always 0.)
7
6
5
4
3
2
1
0
Address
Initial
value
DCHC0
TC0
0
0
0
MLE0
INIT0
STG0
EN0
FFFFF0E0H
00H
7
6
5
4
3
2
1
0
Address
Initial
value
DCHC1
TC1
0
0
0
MLE1
INIT1
STG1
EN1
FFFFF0E2H
00H
7
6
5
4
3
2
1
0
Address
Initial
value
DCHC2
TC2
0
0
0
MLE
INIT
STG
EN2
FFFFF0E4H
00H
7
6
5
4
3
2
1
0
Address
Initial
value
DCHC3
TC3
0
0
0
MLE
INIT
STG
EN3
FFFFF0E6H
00H
Bit position
Bit name
Function
7
TCn
The Terminal Count status bit TC indicates whether DMA transfer through DMA
channel n has ended or not. It is read-only, and is set to 1 when DMA transfer ends
and cleared (0) when it is read.
0: DMA transfer had not ended.
1: DMA transfer had ended.
3
MLEn
When the Multi Link Enable bit MLE is set to 1 at terminal count output, the ENn bit
is not cleared to 0 and the DMA transfer enable state is retained (refer to
“Automatic Restart Function” on page 323
). Moreover, the next DMA transfer
request can be accepted even when the TCn bit is not read, that means it is not
cleared.
When this bit is cleared to 0 at terminal count output, the ENn bit is cleared to 0 and
the DMA transfer disable state is entered. At the next DMA request, the setting of
the ENn bit to 1 and the reading of the TCn bit are required.
2
INITn
When this bit is set to 1, DMA transfer is forcibly terminated.
1
STGn
If this bit is set to 1 in the DMA transfer enable state (TCn bit = 0, ENn bit = 1),
DMA transfer is started.
0
ENn
Specifies whether DMA transfer through DMA channel n is to be enabled or
disabled.
0: DMA transfer disabled
1: DMA transfer enabled
If MLEn=0, this bit is cleared to 0 when DMA transfer ends.
If MLEn=1, this bit is not cleared and the next DMA transfer is automatically
restarted (refer to
“Automatic Restart Function” on page 323
).
This bit is also cleared to 0 when DMA transfer is forcibly terminated by means of
setting the INITn bit to 1 or by NMI input.
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