MC68HC705C9A Datasheet, PDF (37/118 Pages) Motorola, Inc – Microcontrollers

FROM RESET
External Interrupt (IRQ or Port B)
Y
I BIT
IN CCR
SET?
N
IRQ OR PORT B
EXTERNAL
Y
INTERRUPT
N
INTERNAL
TIMER
Y
INTERRUPT
N
INTERNAL
SCI
Y
INTERRUPT
N
INTERNAL
SPI
Y
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
Figure 4-1. Interrupt Flowchart
LOAD PC FROM:
SWI: $3FFC-$3FFD
IRQ: $3FFA-$3FFB
TIMER: $3FF8-$3FF9
SCI: $3FF6-$3FF7
SPI: $3FF4-$3FF5
MC68HC05C9A Advance Information Data Sheet, Rev. 4.1
Freescale Semiconductor
37