mc68hc05l25 Freescale Semiconductor, Inc, mc68hc05l25 Datasheet - Page 45

• Manufacturer Part Number: mc68hc05l25
• Description: M68hc05 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

6.6.3 Interrupt Status Register
IRQF — External Interrupt (IRQ) Flag
Bits 6–5 — Reserved
KWIF — Key Wakeup Interrupt Flag
RIRQF — Reset IRQ Flag
Bits 2–1 — Reserved
RKWIF — Reset KWI Flag
Freescale Semiconductor
A falling edge on the IRQ pin sets the IRQF bit. If the IRQE bit and this bit are set and the interrupt
mask is cleared, an interrupt is generated. This is a read-only bit. Clearing IRQF is accomplished by
writing a one to the RIRQF bit. Reset clears this bit.
These bits are not used and always read zero.
When the KWIEx bit in the KWIEN register is set, the falling edge at the KWIx pin sets the KWIF bit. If
the KWIE bit and this bit are set, an interrupt is generated. This bit is a read-only bit and clearing it is
accomplished by writing a one to the RKWIF bit. Reset clears this bit.
The RIRQF bit is a write-only bit and always read as zero. Writing a one to this bit clears the IRQF bit
and writing zero to this bit has no effect.
These bits are not used and always read zero.
The RKWIF bit is a write-only bit and always read as zero. Writing a one to this bit clears the KWIF bit,
and writing zero to this bit has no effect.
1 = Clear IRQF
0 = No effect
1 = Clear KWIF
0 = No effect
Address:
Reset:
Read:
Write:
$0009
IRQF
Bit 7
0
Figure 6-3. Interrupt Status Register (INSTR)
= Unimplemented
6
0
0
MC68HC05L25 Data Sheet, Rev. 3.1
5
0
0
KWIF
4
0
RIRQF
3
0
0
2
0
0
1
0
0
External Interrupt (IRQ)
RKWIF
Bit 0
0
0
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