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8.5.8
DMAC Activation Sources
DMAC activation sources consist of internal interrupts, external requests, and auto-requests. The
activation sources that can be specified depend on the transfer mode and the channel, as shown in
table 8-12.
Table 8-12 DMAC Activation Sources
Activation Source
Internal
ADI
Interrupts
TXI0
RXI0
TXI1
RXI1
TGI0A
TGI1A
TGI2A
TGI3A
TGI4A
TGI5A
DREQ pin falling edge input
External
Requests
DREQ pin low-level input
Auto-request
Legend
: Can be specified
X : Cannot be specified
Activation by Internal Interrupt: An interrupt request selected as a DMAC activation source
can be sent simultaneously to the CPU and DTC. For details, see section 5, Interrupt Controller.
With activation by an internal interrupt, the DMAC accepts the request independently of the
interrupt controller. Consequently, interrupt controller priority settings are not accepted.
If the DMAC is activated by a CPU interrupt source or an interrupt source that is not used as a
DTC activation source (DTA = 1), the interrupt source flag is cleared automatically by the DMA
transfer. With ADI, TXI, and RXI interrupts, however, the interrupt source flag is not cleared
unless the prescribed register is accessed in a DMA transfer. If the same interrupt is used as an
264
Short Address Mode
Channels
Channels
0A and 1A
0B and 1B
X
X
X
X
Full Address Mode
Block
Normal
Transfer
Mode
Mode
X
X
X
X
X
X
X
X
X
X
X
X
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