Motorola MC68VZ328 用户手册
9-8
MC68VZ328 User’s Manual
Programming Model
9.6.2
Interrupt Control Register
The interrupt control register (ICR) controls the behavior of the external interrupt inputs. It informs the
interrupt controller whether the interrupt signal is an edge-triggered or a level-sensitive interrupt, as well as
whether it has positive or negative polarity. The bit assignments for this register are shown in the following
register display, and the settings for the bit positions are listed in Table 9-4.
interrupt controller whether the interrupt signal is an edge-triggered or a level-sensitive interrupt, as well as
whether it has positive or negative polarity. The bit assignments for this register are shown in the following
register display, and the settings for the bit positions are listed in Table 9-4.
ICR
Interrupt Control Register
0x(FF)FFF302
BIT 15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
BIT 0
POL1
POL2
POL3
POL6
ET1
ET2
ET3
ET6
POL5
TYPE
rw
rw
rw
rw
rw
rw
rw
rw
rw
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0x0000
Table 9-4. Interrupt Control Register Description
Name
Description
Setting
POL1
Bit 15
Bit 15
Polarity Control 1—This bit controls interrupt polarity for the IRQ1 signal. In
level-sensitive mode, negative polarity produces an interrupt when the signal is
at logic level low. Positive polarity produces an interrupt when the signal is at
logic level high. In edge-triggered mode, negative polarity produces an interrupt
when the signal goes from logic level high to logic level low. Positive polarity
generates an interrupt when the signal goes from logic level low to logic level
high.
level-sensitive mode, negative polarity produces an interrupt when the signal is
at logic level low. Positive polarity produces an interrupt when the signal is at
logic level high. In edge-triggered mode, negative polarity produces an interrupt
when the signal goes from logic level high to logic level low. Positive polarity
generates an interrupt when the signal goes from logic level low to logic level
high.
0 = Negative
polarity.
1 = Positive
polarity.
POL2
Bit 14
Bit 14
Polarity Control 2—This bit controls interrupt polarity for the IRQ2 signal. In
level-sensitive mode, negative polarity produces an interrupt when the signal is
at logic level low. Positive polarity produces an interrupt when the signal is at
logic level high. In edge-triggered mode, negative polarity produces an interrupt
when the signal goes from logic level high to logic level low. Positive polarity
generates an interrupt when the signal goes from logic level low to logic level
high.
level-sensitive mode, negative polarity produces an interrupt when the signal is
at logic level low. Positive polarity produces an interrupt when the signal is at
logic level high. In edge-triggered mode, negative polarity produces an interrupt
when the signal goes from logic level high to logic level low. Positive polarity
generates an interrupt when the signal goes from logic level low to logic level
high.
0 = Negative
polarity.
1 = Positive
polarity.
POL3
Bit 13
Bit 13
Polarity Control 3—This bit controls interrupt polarity for the IRQ3 signal. In
level-sensitive mode, negative polarity produces an interrupt when the signal is
at logic level low. Positive polarity produces an interrupt when the signal is at
logic level high. In edge-triggered mode, negative polarity produces an interrupt
when the signal goes from logic level high to logic level low. Positive polarity
generates an interrupt when the signal goes from logic level low to logic level
high.
level-sensitive mode, negative polarity produces an interrupt when the signal is
at logic level low. Positive polarity produces an interrupt when the signal is at
logic level high. In edge-triggered mode, negative polarity produces an interrupt
when the signal goes from logic level high to logic level low. Positive polarity
generates an interrupt when the signal goes from logic level low to logic level
high.
0 = Negative
polarity.
1 = Positive
polarity.
POL6
Bit 12
Bit 12
Polarity Control 6—This bit controls interrupt polarity for the IRQ6 signal. In
level-sensitive mode, negative polarity produces an interrupt when the signal is
at logic level low. Positive polarity produces an interrupt when the signal is at
logic level high. In edge-triggered mode, negative polarity produces an interrupt
when the signal goes from logic level high to logic level low. Positive polarity
generates an interrupt when the signal goes from logic level low to logic level
high.
level-sensitive mode, negative polarity produces an interrupt when the signal is
at logic level low. Positive polarity produces an interrupt when the signal is at
logic level high. In edge-triggered mode, negative polarity produces an interrupt
when the signal goes from logic level high to logic level low. Positive polarity
generates an interrupt when the signal goes from logic level low to logic level
high.
0 = Negative
polarity.
1 = Positive
polarity.
ET1
Bit 11
Bit 11
IRQ1 Edge Trigger Select—When this bit is set, the IRQ1 signal is an
edge-triggered interrupt. In edge-triggered mode, a 1 must be written to the
IRQ1 bit in the interrupt status register to clear this interrupt. When this bit is
low, IRQ1 is a level-sensitive interrupt. In this case, the external source of the
interrupt must be cleared.
edge-triggered interrupt. In edge-triggered mode, a 1 must be written to the
IRQ1 bit in the interrupt status register to clear this interrupt. When this bit is
low, IRQ1 is a level-sensitive interrupt. In this case, the external source of the
interrupt must be cleared.
0 = Level-sensitive
interrupt.
1 = Edge-sensitive
interrupt.