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Chapter 7
DMA Functions (DMA Controller)
Preliminary User’s Manual U15839EE1V0UM00
7.2.5 DMA channel control registers 0 to 3 (DCHC0 to DCHC3)
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.)
Figure 7-7:
DMA Channel Control Registers 0 to 3 (DCHC0 to DCHC3)
Remark:
n = 0 to 3
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
This status bit 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 this bit is set to 1 at terminal count output, the Enn bit is not cleared to 0 and
the DMA transfer enable state is retained. Moreover, the next DMA transfer request
can be accepted even when the TCn bit is not read.
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.
This bit is cleared to 0 when DMA transfer ends. It is also cleared to 0 when DMA
transfer is forcibly terminated by means of setting the INITn bit to 1 or by NMI input.
0: DMA transfer disabled
1: DMA transfer enabled
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