HD6432646 Hitachi, HD6432646 Datasheet - Page 160

• Manufacturer Part Number: HD6432646
• Description: (HD64F264x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

5.6.3
The interrupt controller has three main functions in DTC control.
Selection of Interrupt Source: Interrupt factors are selected as DTC activation request or CPU
interrupt request by the DTCE bit of DTCERA to DTCERG, and DTCERI of DTC.
By specifying the DISEL bit of the DTC’s MRB, it is possible to clear the DTCE bit to 0 after
DTC data transfer, and request a CPU interrupt.
If DTC carries out the designate number of data transfers and the transfer counter reads 0, after
DTC data transfer, the DTCE bit is also cleared to 0, and a CPU interrupt requested.
Determination of Priority: The DTC activation source is selected in accordance with the default
priority order, and is not affected by mask or priority levels. See section 8.3.3, DTC Vector Table
for the respective priority.
Operation Order: If the same interrupt is selected as a DTC activation source and a CPU
interrupt source, the DTC data transfer is performed first, followed by CPU interrupt exception
handling.
Table 5-11 shows the interrupt factor clear control and selection of interrupt factors by
specification of the DTCE bit of DTCERA to DTCERG, DTCERI of DTC, and the DISEL bit of
DTC’s MRB.
126
On-chip
supporting
module
IRQ
interrupt
Operation
Interrupt source
clear signal
Interrupt
request
Interrupt controller
Figure 5-9 Interrupt Control for DTC
Selection
DTVECR
DTCER
circuit
Select
signal
clear signal
Clear signal
SWDTE
Determination of
Control logic
priority
DTC activation
request vector
number
CPU interrupt
request vector
number
Clear signal
I, I2 to I0
CPU
DTC