HD64F2149 Datasheet, PDF (208/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

Source flag cleared
Clear
DTCER
Select
Clear
control
Clear request
On-chip
supporting
module
DTC
IRQ interrupt
DTVECR
Interrupt
request
Interrupt controller
Interrupt mask
CPU
Figure 7.3 Block Diagram of DTC Activation Source Control
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 is activated in accordance with the default priorities.
7.3.3 DTC Vector Table
Figure 7.4 shows the correspondence between DTC vector addresses and register information.
Table 7.4 shows the correspondence between activation sources, vector addresses, and DTCER
bits. When the DTC is activated by software, the vector address is obtained from: H'0400 +
DTVECR[6:0] << 1 (where << 1 indicates a 1-bit left shift). For example, if DTVECR is H'10, the
vector address is H'0420.
The DTC reads the start address of the register information from the vector address set for each
activation source, and then reads the register information from that start address. The register
information can be placed at predetermined addresses in the on-chip RAM. The start address of
the register information should be an integral multiple of four.
The configuration of the vector address is the same in both normal and advanced modes, a 2-byte
unit being used in both cases. These two bytes specify the lower bits of the address in the on-chip
RAM.
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