XC68HC705JJ7 Motorola, XC68HC705JJ7 Datasheet - Page 53

• Manufacturer Part Number: XC68HC705JJ7
• Description: MICROCONTROLLER
• Manufacturer: Motorola

4.4 Interrupt Processing
MC68HC705JJ7 • MC68HC705JP7 — REV 4
MOTOROLA
To begin servicing an interrupt, the CPU does these actions:
The return-from-interrupt (RTI) instruction causes the CPU to recover its
register contents from the stack as shown in
of events caused by an interrupt is shown in the flowchart in
•
•
•
$00BE
$00BF
$00C0
$00C1
$00C2
$00FD
$00FE
$00FF
$0020
$0021
n+1
n+2
n+3
n+4
Stores the CPU registers on the stack in the order shown in
Figure 4-1
Sets the I bit in the condition code register to prevent further
interrupts
Loads the program counter with the contents of the appropriate
interrupt vector locations as shown in
n
Figure 4-1. Interrupt Stacking Order
Program Counter (High Byte)
Program Counter (Low Byte)
Condition Code Register
Top of Stack (RAM)
Bottom of Stack
Bottom of RAM
Interrupts
Index Register
Accumulator
Stacking
Order
Table 4-1
Figure
5
4
3
2
1
4-1. The sequence
Unstacking
Advance Information
Interrupt Processing
Order
1
2
3
4
5
Figure
Interrupts
4-2.
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