MC68HC05C9A Datasheet, PDF (32/124 Pages) Freescale Semiconductor, Inc – Microcontrollers

Interrupts
FROM RESET
Y
I BIT
IN CCR
SET?
N
IRQ OR PORT B
Y
EXTERNAL
INTERRUPT
N
INTERNAL
Y
TIMER
INTERRUPT
N
INTERNAL
SCI
Y
INTERRUPT
N
INTERNAL
Y
SPI
INTERRUPT
N
FETCH NEXT
INSTRUCTION
CLEAR IRQ
REQUEST LATCH
STACK
PC, X, A, CCR
SET I BIT IN
CC REGISTER
SWI
Y
INSTRUCTION
?
N
Y
RESTORE REGISTERS
FROM STACK:
CCR, A, X, PC
RTI
INSTRUCTION
?
N
EXECUTE
INSTRUCTION
LOAD PC FROM:
SWI: $3FFC–$3FFD
IRQ: $3FFA–$3FFB
TIMER: $3FF8–$3FF9
SCI: $3FF6–$3FF7
SPI: $3FF4–$3FF5
Figure 4-1. Interrupt Flowchart
MC68HC05C9A Advance Information Data Sheet, Rev. 5.1
32
Freescale Semiconductor