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M30245 Group
Interrupts
Rev.2.00
Oct 16, 2006
page 62 of 264
REJ03B0005-0200
INT interrupt
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INT0 to INT2 are triggered by the edges of external inputs. The edge polarity is selected using the polarity select bit in the
interrupt control register (004416, 005E16, 005F16) and the polarity switching bit in the interrupt request cause select
register (035F16).
For an external interrupt input, an interrupt can be generated both at the rising edge and at the falling edge by setting "1"
in the INTi interrupt polarity switching bit of the interrupt request cause select register (035F16). To select one edge, set
the polarity switching bit of the corresponding interrupt request cause select register to "one edge" ("0"), and set the
polarity select bit in the interrupt control register to rising edge or falling edge.
Figure 1.36 shows the interrupt request cause select register.
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NMI Interrupt
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An NMI interrupt is generated when the input to the P85/NMI pin changes from "H" to "L". The NMI interrupt is a non-
maskable external interrupt. The pin level can be checked in the Port P85 register (bit 5 at address 03F016). This pin
cannot be used as a normal port input.
______
Notes: When not intending to use the NMI function, be sure to connect the NMI pin to Vcc. Because the NMI interrupt is
non-maskable, it cannot be disabled.
______
When the NMI pin input is "L", do not set the microcomputer in stop mode or wait mode. The NMI interrupt is triggered
by the falling edge, so the "L" level does not need to be maintained longer than necessary.
Key-Input Interrupt
A Key input interrupt can be generated by a falling edge, rising edge or both edges input to any Port 10 pin. It can also
be used as a Key-on wake up function for canceling the wait mode or stop mode. Figure 1.37 shows the block diagram
of the Key-input interrupt.
Figure 1.38 shows the Key-input mode register. It is possible to select both edges or the falling edge of the Key input
interrupt for P10 with bits 0 and 1 of this register. This register is also used to enable or disable Port 10 pins that are to
be used for Key-input interrupts. Port 10 can be configured with pull-up resistors using the pull-up control resistor.
Interrupt request cause select register
Bit name
Function
Bit symbol
W
R
Symbol
Address
When reset
IFSR
035F16
0016
IFSR0
b7
b6
b5
b4
b3
b2
b1
b0
INT0 interrupt polarity
swiching bit
0 : One edge
1 : Two edges
0 : One edge
1 : Two edges
0 : One edge
1 : Two edges
Nothing is assigned.
Write "0" when writing to these bits. The value is indeterminate when read.
INT1 interrupt polarity
swiching bit
INT2 interrupt polarity
swiching bit
IFSR1
IFSR2
IFSR6
IFSR7
0 : UART0 Bus collision
1 : UART2 Bus collision
0 : UART1 Bus collision
1 :
UART3 Bus collision
Bus collision interrupt request
cause select bit 0
Bus collision interrupt request
cause select bit 1