mc68hc908mr8 Freescale Semiconductor, Inc, mc68hc908mr8 Datasheet - Page 303

• Manufacturer Part Number: mc68hc908mr8
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

16.9 IRQ Status and Control Register
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor
The IRQ status and control register (ISCR) has these functions:
ACK1 — IRQ Interrupt Request Acknowledge Bit
IMASK1 — IRQ Interrupt Mask Bit
MODE1 — IRQ Edge/Level Select Bit
IRQF — IRQ Flag
Reset:
dress:
Read:
Write:
Ad-
•
•
•
Writing a logic 1 to this write-only bit clears the IRQ latch. ACK1
always reads as logic 0. Reset clears ACK1.
Writing a logic 1 to this read/write bit disables IRQ interrupt requests.
Reset clears IMASK1.
This read/write bit controls the triggering sensitivity of the IRQ pin.
Reset clears MODE1.
This read-only bit acts as a status flag, indicating an IRQ event
occurred.
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
1 = External IRQ event occurred.
0 = External IRQ event did not occur.
Clears the IRQ interrupt latch
Masks IRQ interrupt requests
Controls triggering sensitivity of the IRQ interrupt pin
Figure 16-4. IRQ Status and Control Register (ISCR)
$003F
Bit 7
R
R
0
0
External Interrupt (IRQ)
= Reserved
R
6
0
0
R
5
0
0
R
4
0
0
IRQF
3
0
IRQ Status and Control Register
ACK1
2
0
0
External Interrupt (IRQ)
IMASK1 MODE1
1
0
Technical Data
Bit 0
0
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