MC68HC11PH8 Datasheet, PDF (204/264 Pages) Motorola, Inc – High-density Complementary Metal Oxide Semiconductor (HCMOS) Microcomputer Unit

10
1B
Yes
I-bit in
CCR set?
No
I-bit interrupt
pending?
Yes
Stack
CPU registers
No
Stack CPU registers.
Set I bit.
No
Fetch vector at
$FFF8, $FFF9
Stack CPU registers.
Set I bit.
Yes
Fetch vector at
$FFF6, $FFF7
Restore
CPU registers
Yes
from Stack
Fetch
opcode
Legal
opcode?
Yes
WAI?
No
SWI?
No
RTI?
Yes
Stack
CPU registers
Interrupt
No
yet?
Yes
Set I-bit
No
Execute this
instruction
Resolve interrupt
priority and fetch vector
for highest pending
source (Figure 10-3)
1A
Start next instruction
sequence
MOTOROLA
10-20
Figure 10-2 Processing flow out of reset (2 of 2)
RESETS AND INTERRUPTS
TPG
MC68HC11PH8