HD6432621 Hitachi, HD6432621 Datasheet - Page 154

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

(2) 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
(3) 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.
110
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
X
8-Level Control
I2 to I0
—
IM
IPR
—*
PR
2
Default Priority
Determination
T
(Trace)
—
T