Dtc Vector Table - Hitachi H8S/2646 Hardware Manual

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.
8.3.3

DTC Vector Table

Figure 8-4 shows the correspondence between DTC vector addresses and register information.
Table 8-4 shows the correspondence between activation and vector addresses. 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.
Note: * Not available in the H8S/2646 Series.
DTC vector
address
Figure 8-4 Correspondence between DTC Vector Address and Register Information
Register information
start address
Register information
Chain transfer
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