116
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
Interrupts Selected in Each Interrupt Control Mode (2)
Interrupt Control Mode
Selected Interrupts
0
All interrupts
2
Highest-priority-level (IPR) interrupt whose priority level is greater
than the mask level (IPR > I2 to I0).
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
Operations and Control Signal Functions in Each Interrupt Control Mode
Interrupt
Control
Setting
Interrupt Acceptance
Control
8-Level Control
Default Priority
T
Mode
INTM1
INTM0
I
I2 to I0
IPR
Determination
(Trace)
0
0
0
IM
X
—
—
*
2
—
2
1
0
X
—
*
1
IM
PR
T
Legend
: Interrupt operation control performed
X : No operation. (All interrupts enabled)
IM : Used as interrupt mask bit
PR : Sets priority.
— : Not used.
Notes:
*
1 Set to 1 when interrupt is accepted.
*
2 Keep the initial setting.
Summary of Contents for H8S/2645
Page 4: ......
Page 16: ......
Page 58: ...26 ...
Page 110: ...78 ...
Page 120: ...88 ...
Page 132: ...100 ...
Page 160: ...128 ...
Page 172: ...140 ...
Page 418: ...386 ...
Page 444: ...412 ...
Page 530: ...498 ...
Page 562: ...530 ...
Page 642: ...610 ...
Page 662: ...630 ...
Page 688: ...656 ...
Page 756: ...724 ...
Page 784: ...752 ...
Page 812: ...780 ...
Page 837: ...805 A 2 Instruction Codes Table A 2 shows the instruction codes ...
Page 1152: ...1120 ...