Datasheet

Section 9 Data Transfer Controller (DTC)
Rev. 3.00 Mar 17, 2006 page 407 of 926
REJ09B0283-0300
9.3 Activation Sources
The DTC operates when activated by an interrupt or by a write to DTVECR by software. An
interrupt request can be directed to the CPU or DTC, as designated by the corresponding DTCER
bit. At the end of a data transfer (or the last consecutive transfer in the case of chain transfer), the
activation source or corresponding DTCER bit is cleared. The activation source flag, in the case of
RXI0, for example, is the RDRF flag of SCI_0.
When an interrupt has been designated a DTC activation source, existing CPU mask level and
interrupt controller priorities have no effect. If there is more than one activation source at the same
time, the DTC operates in accordance with the default priorities.
Figure 9.2 shows a block diagram of activation source control. For details see section 5, Interrupt
Controller.
CPU
DTC
DTCER
Source flag cleared
On-chip
supporting
module
IRQ interrupt
Interrupt
request
Clear
Clear
controller
Clear request
Interrupt controller
Selection circuit
Interrupt mask
Select
DTVECR
Figure 9.2 Block Diagram of DTC Activation Source Control