Datasheet

V850ES/JG3 CHAPTER 18 DMA FUNCTION (DMA CONTROLLER)
R01UH0015EJ0300 Rev.3.00 Page 617 of 870
Sep 30, 2010
(4) DMA addressing control registers 0 to 3 (DADC0 to DADC3)
The DADC0 to DADC3 registers are 16-bit registers that control the DMA transfer mode for DMA channel n (n = 0
to 3).
These registers can be read or written in 16-bit units.
Reset sets these registers to 0000H.
DADCn
(n = 0 to 3)
8 bits
16 bits
DS0
0
1
Setting of transfer data size
Increment
Decrement
Fixed
Setting prohibited
SAD1
0
0
1
1
SAD0
0
1
0
1
Setting of count direction of the transfer source address
Increment
Decrement
Fixed
Setting prohibited
DAD1
0
0
1
1
DAD0
0
1
0
1
Setting of count direction of the destination address
After reset: 0000H R/W Address: DADC0 FFFFF0D0H, DADC1 FFFFF0D2H,
DADC2 FFFFF0D4H, DADC3 FFFFF0D6H
SAD1 SAD0 DAD1 DAD0 0 0 0 0
0DS000 00 0 0
89101112131415
01234567
Cautions 1. Be sure to clear bits 15, 13 to 8, and 3 to 0 of the DADCn register to “0”.
2. Set the DADCn register at the following timing when DMA transfer is disabled (DCHCn.Enn
bit = 0).
• Period from after reset to start of first DMA transfer
• Period from after channel initialization by DCHCn.INITn bit to start of DMA transfer
• Period from after completion of DMA transfer (DCHCn.TCn bit = 1) to start of the next
DMA transfer
3. The DS0 bit specifies the size of the transfer data, and does not control bus sizing. If 8-bit
data (DS0 bit = 0) is set, therefore, the lower data bus is not always used.
4. If the transfer data size is set to 16 bits (DS0 bit = 1), transfer cannot be started from an
odd address. Transfer is always started from an address with the first bit of the lower
address aligned to 0.
5. If DMA transfer is executed on an on-chip peripheral I/O register (as the transfer source or
destination), be sure to specify the same transfer size as the register size. For example, to
execute DMA transfer on an 8-bit register, be sure to specify 8-bit transfer.