h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 183

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 8 Data Transfer Controller (DTC)
8.3
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 RXI_0, for example, is the RDRF flag of SCI_0.
When an interrupt has been designated a DTC activation source, the 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 8.2 shows a block diagram of DTC activation source control. For details, see section 5,
Interrupt Controller.
Source flag cleared
Clear
controller
Clear
DTCER
Clear request
Select
On-chip
DTC
supporting
module
IRQ interrupt
Interrupt
request
CPU
Interrupt controller
DTVECR
Interrupt mask
Figure 8.2 Block Diagram of DTC Activation Source Control
Rev. 2.00 Dec. 05, 2005 Page 145 of 724
REJ09B0200-0200