mc68hc908rf2 Freescale Semiconductor, Inc, mc68hc908rf2 Datasheet - Page 97

• Manufacturer Part Number: mc68hc908rf2
• Description: M68hc08 Microcontrollers Microcontroller / Transmitter
• Manufacturer: Freescale Semiconductor, Inc

MC68HC908RF2 — Rev. 4.0
MOTOROLA
NOTE:
If the MODEI bit is clear, the IRQ pin is falling-edge sensitive only. With MODEI
clear, a vector fetch or software clear immediately clears the IRQ1 latch.The IRQ1F
bit in the INTKBSCR register can be used to check for pending interrupts. The
IRQ1F bit is not affected by the IMASKI bit, which makes it useful in applications
where polling is preferred.
Use the BIH or BIL instruction to read the logic level on the IRQ pin.
When using the level-sensitive interrupt trigger, avoid false interrupts by masking
interrupt requests in the interrupt routine.
Freescale Semiconductor, Inc.
For More Information On This Product,
YES
Keyboard/External Interrupt Module (KBI)
Go to: www.freescale.com
INSTRUCTION?
INSTRUCTION?
INSTRUCTION
FROM RESET
INTERRUPT?
FETCH NEXT
I BIT SET?
Figure 7-4. IRQ Interrupt Flowchart
SWI
RTI
NO
NO
NO
NO
YES
YES
YES
LOAD PC WITH INTERRUPT VECTOR
UNSTACK CPU REGISTERS
EXECUTE INSTRUCTION
STACK CPU REGISTERS
Keyboard/External Interrupt Module (KBI)
SET I BIT
Functional Description
Data Sheet
97