p2125vps20 Renesas Electronics Corporation., p2125vps20 Datasheet - Page 171

• Manufacturer Part Number: p2125vps20
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 7 Data Transfer Controller (DTC)
7.3
Activation Sources
The DTC is activated by an interrupt request or by a write to DTVECR by software. The interrupt
request source to activate the DTC is selected by DTCER. At the end of a data transfer (or the last
consecutive transfer in the case of chain transfer), the interrupt flag that became the activation
source or the corresponding DTCER bit is cleared. The activation source flag, in the case of RXI1,
for example, is the RDRF flag in SCI_1.
When an interrupt has been designated as 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 7.2 shows a block
diagram of DTC activation source control. For details on the interrupt controller, see section 5,
Interrupt Controller.
Source flag cleared
Clear
controller
Clear
DTCER
Clear request
Select
On-chip
DTC
peripheral
module
IRQ interrupt
Interrupt
request
Interrupt controller
CPU
DTVECR
Interrupt mask
Figure 7.2 Block Diagram of DTC Activation Source Control
Rev. 1.00 Sep. 21, 2006 Page 133 of 658
REJ09B0310-0100