CHAPTER 7 DMAC
Preliminary User’s Manual A14874EJ3V0UM
157
7.5.4 DMA addressing control registers 0 to 3 (DADC0 to DADC3)
These 16-bit registers are used to control the DMA transfer operation mode for DMA channels n (n = 0 to 3).
These registers can be read or written in 16-bit units.
Caution These registers cannot be accessed during a DMA transfer.
Figure 7-6. DMA Addressing Control Registers 0 to 3 (DADC0 to DADC3) (1/2)
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
DADC0
DS
1
DS
0
0
0
0
0
0
0
SAD
1
SAD
0
DAD
1
DAD
0
TM1 TM0 TTYP TDIR
Address
FFFFF0D0H
After reset
0000H
DADC1
DS
1
DS
0
0
0
0
0
0
0
SAD
1
SAD
0
DAD
1
DAD
0
TM1 TM0 TTYP TDIR
Address
FFFFF0D2H
After reset
0000H
DADC2
DS
1
DS
0
0
0
0
0
0
0
SAD
1
SAD
0
DAD
1
DAD
0
TM1 TM0 TTYP TDIR
Address
FFFFF0D4H
After reset
0000H
DADC3
DS
1
DS
0
0
0
0
0
0
0
SAD
1
SAD
0
DAD
1
DAD
0
TM1 TM0 TTYP TDIR
Address
FFFFF0D6H
After reset
0000H
Bit position
Bit name
Function
Sets the transfer data size for a DMA transfer.
DS1
DS0
Transfer data size
0
0
8 bits
0
1
16 bits
1
0
32 bits
1
1
Setting prohibited
15, 14
DS1,
DS0
Cautions 1. Bits DS1 and DS0 are used to set the number of bits of data to be transferred. Which
data bus line to be used is determined by the VMBENZ3 to VMBENZ0 signals.
Therefore, even if 8-bit data is set (DS1, DS0 = 0, 0), the lower data bus (DATA7 to
DATA0) may not always be used.
When the transfer data size is set to 16 bits, transfer must be started from the address
with the lowest bit aligned to 0, and from the address with the two lowest bits aligned to
0 in the case of 32 bits. In both cases, transfer starting at an odd address is not
possible.
2. Bits 13 to 8 of the DADC0 to DADC3 registers must be set to 0. The operation when
these bits are set to 1 is not guaranteed.