MC68HC908RF2 Datasheet, PDF (187/254 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Keyboard/External Interrupt Module (KBI)
Functional Description
NOTE:
The interrupt mask (I) in the condition code register (CCR) masks all
interrupt requests, including external interrupt requests.
See Figure 14-3.
FROM RESET
YES
I BIT SET?
NO
INTERRUPT?
NO
YES
STACK CPU REGISTERS
SET I BIT
LOAD PC WITH INTERRUPT VECTOR
FETCH NEXT
INSTRUCTION
SWI
YES
INSTRUCTION?
NO
RTI
YES
INSTRUCTION?
NO
UNSTACK CPU REGISTERS
EXECUTE INSTRUCTION
Figure 14-3. IRQ Interrupt Flowchart
MC68HC908RF2
MOTOROLA
Keyboard/External Interrupt Module (KBI)
Advance Information
187