HD6432646 Hitachi, HD6432646 Datasheet - Page 150

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

8-Level Control: In interrupt control mode 2, 8-level mask level determination is performed for
the selected interrupts in interrupt acceptance control according to the interrupt priority level
(IPR).
The interrupt source selected is the interrupt with the highest priority level, and whose priority
level set in IPR is higher than the mask level.
Table 5-7
Interrupt Control Mode
0
2
Default Priority Determination: When an interrupt is selected by 8-level control, its priority is
determined and a vector number is generated.
If the same value is set for IPR, acceptance of multiple interrupts is enabled, and so only the
interrupt source with the highest priority according to the preset default priorities is selected and
has a vector number generated.
Interrupt sources with a lower priority than the accepted interrupt source are held pending.
Table 5-8 shows operations and control signal functions in each interrupt control mode.
Table 5-8
Interrupt
Control
Mode
0
2
Legend
Notes: *1 Set to 1 when interrupt is accepted.
116
PR : Sets priority.
IM : Used as interrupt mask bit
— : Not used.
X : No operation. (All interrupts enabled)
: Interrupt operation control performed
*2 Keep the initial setting.
INTM1 INTM0
0
1
Interrupts Selected in Each Interrupt Control Mode (2)
Operations and Control Signal Functions in Each Interrupt Control Mode
Setting
0
0
Interrupt Acceptance
Control
X
Selected Interrupts
All interrupts
Highest-priority-level (IPR) interrupt whose priority level is greater
than the mask level (IPR > I2 to I0).
I
IM
—
* 1
8-Level Control
X —
I2 to I0
IM
IPR
—
PR
*2
Default Priority
Determination
T
(Trace)
—
T