CHAPTER 6 DMA FUNCTIONS (DMA CONTROLLER)
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User’s Manual U14492EJ3V0UD
6.3.4 DMA addressing control registers 0 to 3 (DADC0 to DADC3)
These 16-bit registers are used to control the DMA transfer modes for DMA channel n (n = 0 to 3). These registers
cannot be accessed during DMA operation.
These registers can be read/written in 16-bit units.
Be sure to set bits 0, 1, and 8 to 13 to 0. If they are set to 1, the operation is not guaranteed.
Cautions 1. The DS1 and DS0 bits are used to set how many bits of data are transferred.
When 8-bit data (DS1, DS0 bits = 00) is set, the lower data bus (AD0 to AD7) is not necessarily
used.
When the transfer data size is set to 16 bits, the transfer must start from an address with bit 1
of the lower address aligned to “0”. In this case, the transfer cannot start from an odd
address.
2. Set the DADCn register when the corresponding channel is in one of the following periods
(the operation is not guaranteed if set at another timing).
••••
Time from system reset to the start of the first DMA transfer
••••
Time from DMA transfer end (after terminal count) to the start of the next DMA transfer
•
Time from the forcible termination of DMA transfer (after the INITn bit of DMA channel
control register n (DCHCn) has been set to 1) to the start of the next DMA transfer
(1/2)
15
DS1
DADC0
Address
FFFFF0D0H
Initial value
0000H
14
DS0
13
0
12
0
11
0
10
0
9
0
8
0
7
SAD1
6
SAD0
5
DAD1
4
DAD0
3
TM1
2
TM0
1
0
0
0
DS1
DADC1
FFFFF0D2H
0000H
DS0
0
0
0
0
0
0
SAD1 SAD0 DAD1 DAD0 TM1 TM0
0
0
DS1
DADC2
FFFFF0D4H
0000H
DS0
0
0
0
0
0
0
SAD1 SAD0 DAD1 DAD0 TM1 TM0
0
0
DS1
DADC3
FFFFF0D6H
0000H
DS0
0
0
0
0
0
0
SAD1 SAD0 DAD1 DAD0 TM1 TM0
0
0
Bit Position
Bit Name
Function
Sets the transfer data size for DMA transfer.
DS1
DS0
Transfer Data Size
0
0
8 bits
0
1
16 bits
1
0
Setting prohibited
1
1
Setting prohibited
15, 14
DS1, DS0
For the on-chip peripheral I/O and programmable peripheral I/O registers, ensure the
transfer size matches the access size.
Содержание V850E/IA1 mPD703116
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