mc68hc908qf4 Freescale Semiconductor, Inc, mc68hc908qf4 Datasheet - Page 77

• Manufacturer Part Number: mc68hc908qf4
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

8.6 IRQ Status and Control Register
MC68HC908QF4 — Rev. 1.0
MOTOROLA
To allow software to clear the IRQ latch during a break interrupt, write a 1 to the
BCFE bit. If a latch is cleared during the break state, it remains cleared when the
MCU exits the break state.
To protect the latches during the break state, write a 0 to the BCFE bit. With BCFE
at 0 (its default state), writing to the ACK bit in the IRQ status and control register
during the break state has no effect on the IRQ latch.
The IRQ status and control register (ISCR) controls and monitors operation of the
IRQ module, see
The ISCR has the following functions:
IRQF — IRQ Flag
ACK — IRQ Interrupt Request Acknowledge Bit
IMASK — IRQ Interrupt Mask Bit
MODE — IRQ Edge/Level Select Bit
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Address: $001D
This read-only status bit is high when the IRQ interrupt is pending.
Writing a 1 to this write-only bit clears the IRQ latch. ACK always reads as 0.
Reset clears ACK.
Writing a 1 to this read/write bit disables IRQ interrupt requests. Reset clears
IMASK.
This read/write bit controls the triggering sensitivity of the IRQ pin. Reset clears
MODE.
Reset:
Read:
Write:
1 = IRQ interrupt pending
0 = IRQ interrupt not pending
1 = IRQ interrupt requests disabled
0 = IRQ interrupt requests enabled
1 = IRQ interrupt requests on falling edges and low levels
0 = IRQ interrupt requests on falling edges only
Shows the state of the IRQ flag
Clears the IRQ latch
Masks IRQ and interrupt request
Controls triggering sensitivity of the IRQ interrupt pin
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 8-4. IRQ Status and Control Register (INTSCR)
Bit 7
0
0
Go to: www.freescale.com
Section 5. Configuration Register
= Unimplemented
External Interrupt (IRQ)
6
0
0
5
0
0
4
0
0
IRQF
3
0
IRQ Status and Control Register
(CONFIG).
ACK
2
0
External Interrupt (IRQ)
IMASK
1
0
Data Sheet
MODE
Bit 0
0
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