2.
Interrupts IRQ
4
to IRQ
0
Interrupts IRQ
4
to IRQ
0
are requested by input signals to pins
IRQ
4
to
IRQ
0
. These interrupts are
detected by either rising edge sensing or falling edge sensing, depending on the settings of bits IEG4
to IEG0 in IEGR.
When these pins are designated as pins
IRQ
4
to
IRQ
0
in port mode register 3 and 1 and the
designated edge is input, the corresponding bit in IRR1 is set to 1, requesting an interrupt.
Recognition of these interrupt requests can be disabled individually by clearing bits IEN4 to IEN0
to 0 in IENR1. These interrupts can all be masked by setting the I bit to 1 in CCR.
When IRQ
4
to IRQ
0
interrupt exception handling is initiated, the I bit is set to 1 in CCR. Vector
numbers 8 to 4 are assigned to interrupts IRQ
4
to IRQ
0
. The order of priority is from IRQ
0
(high) to
IRQ
4
(low). Table 3-2 gives details.
3.3.4 Internal Interrupts
There are 23 internal interrupts that can be requested by the on-chip peripheral modules. When a
peripheral module requests an interrupt, the corresponding bit in IRR1 or IRR2 is set to 1.
Recognition of individual interrupt requests can be disabled by clearing the corresponding bit in
IENR1 or IENR2. All these interrupts can be masked by setting the I bit to 1 in CCR. When internal
interrupt handling is initiated, the I bit is set to 1 in CCR. Vector numbers from 20 to 11 are
assigned to these interrupts. Table 3-2 shows the order of priority of interrupts from on-chip
peripheral modules.
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