User’s Manual U13850EJ4V0UM
360
CHAPTER 12 DMA FUNCTIONS
12.1 Functions
The DMA (Direct Memory Access) controller transfers data between memory and peripheral I/Os based on DMA
requests sent from on-chip peripheral hardware (such as the serial interface, timer, or A/D converter).
This product includes six independent DMA channels that can transfer data in 8-bit and 16-bit units. The
maximum number of transfers is 256 (when transferring data in 8-bit units).
After a DMA transfer has occurred a specified number of times, DMA transfer completion interrupt (INTDMA0 to
INTDMA5) requests are output individually from the various channels.
The priority levels of the DMA channels are fixed as follows for simultaneous generation of multiple DMA transfer
requests.
DMA0 > DMA1 > DMA2 > DMA3 > DMA4 > DMA5
12.2 Transfer Completion Interrupt Request
After a DMA transfer has occurred a specified number of times and the TCn bit in the corresponding DMA channel
control register (DCHCn) has been set to 1, a DMA transfer completion interrupt request (INTDMA0 to INTDMA5)
occurs on each channel in relation to the interrupt controller.
12.3 Control Registers
12.3.1 DMA peripheral I/O address registers 0 to 5 (DIOA0 to DIOA5)
These registers are used to set the peripheral I/O register’s address for DMA channel n.
These registers are can be read/written in 16-bit units.
Figure 12-1. Format of DMA Peripheral I/O Address Registers 0 to 5 (DIOA0 to DIOA5)
After reset: Undefined
R/W
Address: DIOA0
FFFFF180H
DIOA3
FFFFF1B0H
DIOA1
FFFFF190H
DIOA4
FFFFF1C0H
DIOA2
FFFFF1A0H
DIOA5
FFFFF100H
15
14
13
12
11
10
9
1
0
DIOAn
0
0
0
0
0
0
IOAn9 to IOAn1
0
(n = 0 to 5)
Caution The following peripheral I/O registers must not be set.
P4, P5, P6, P9, P11, PM4, PM5, PM6, PM9, PM11, MM, DWC, BCC, SYC, PSC, PCC, SYS,
PRCMD, DIOAn, DRAn, DBCn, DCHCn, CORCN, CORRQ, CORADn, Interrupt control register
(xxICn), ISPR
Содержание MPD703030A
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