mc68hc08qa24 Freescale Semiconductor, Inc, mc68hc08qa24 Datasheet - Page 186

• Manufacturer Part Number: mc68hc08qa24
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

External Interrupt (IRQ)
15.7 IRQ Status and Control Register
Technical Data
184
Address: $001A
The IRQ status and control register (ISCR) controls and monitors
operation of the IRQ module. The ISCR has these functions:
IRQF — IRQ Flag
ACK — IRQ Interrupt Request Acknowledge Bit
IMASK — IRQ Interrupt Mask Bit
MODE — IRQ Edge/Level Select Bit
Reset:
Read:
Write:
•
•
•
•
This read-only status bit is high when the IRQ interrupt is pending.
Writing a logic 1 to this write-only bit clears the IRQ latch. ACK always
reads as logic 0. Reset clears ACK.
Writing a logic 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.
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 interrupt flag
Clears the IRQ interrupt latch
Masks IRQ interrupt request
Controls triggering sensitivity of the IRQ interrupt pin
Figure 15-3. IRQ Status and Control Register (ISCR)
Bit 7
R
R
0
0
External Interrupt (IRQ)
= Reserved
R
6
0
0
R
5
0
0
R
4
0
0
IRQF
R
3
0
ACK
Freescale Semiconductor
2
0
0
MC68HC08QA24
IMASK
1
0
MODE
Bit 0
0