M30222 Datasheet, PDF (48/237 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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MITSUBISHI MICROCOMPUTERS
Specifications in this manual are tentative and subject to change
M30222 Group
Rev. G
Overview of Interrupts
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
INT Interrupt
INT0 to INT7 are triggered by the edges of external inputs. The edge polarity is selected using the polarity
select bit. The interrupt control registers, 005816 is used both as Timer A3 and external interrupt INT4 input
control register, and 005916 is used both as Timer A4 and as external interrupt INT5 input control register.
Also, 005F16 is used as both SIO3 and external interrupt INT2 input control register and 004416 is used as
both SIO4 and external interrupt INT3 input control register. Use the interrupt request cause select bits - bits
4, 5, 6 and 7 of the interrupt request cause select register 0 (address 035E16) - to specify which interrupt
request cause to select. When INT4 is selected as an interrupt source, the input port for it can be selected by
bits 0 and 1 of the interrupt source select register 0 (address 035E16). Similarly, when INT5 is selected as an
interrupt source, the input port for it can be selected by bits 2 and 3 of the interrupt source select register 0
(address 035E16). After having set an interrupt request cause and interrupt input ports, be sure to set the
corresponding interrupt request bit to "0" before enabling an interrupt.
The interrupt control registers - 005816, 005916, 005F16, and 004416 - have the polarity-switching bit. Be sure
to set this bit to “0” to select a timer or SIO as the interrupt request cause.
The external interrupt input 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 1 (035F16). To select two
edges, set the polarity switching bit of the corresponding interrupt control register to ‘falling edge’ (“0”).
When INT4 input pin select bits = "11", INT4 interupt polarity switching bit = "0", and polarity select bit = "1" of
the INT4 interrupt control register, an interrupt is generated by a rising edge on the input port when the
exclusive pin is "H", as shown by "Single edge, Rise" in Figure 1.32. When the exclusive pin is "H", interrupts
can only be generated by an active transition on a single edge. The same applies to INT5.
Figure 1.30 shows the Interrupt request cause select registers. Figure 1.31 shows the block diagram of INT4
and INT5.
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