MC68000 MOTOROLA [Motorola, Inc], MC68000 Datasheet - Page 39

• Manufacturer Part Number: MC68000
• Manufacturer: MOTOROLA [Motorola, Inc]

2.4.2 Exception Stacking Order
Exception processing saves the most volatile portion of the current processor context on top
of the supervisor stack. This context is organized in a format called the exception stack
frame. The amount and type of information saved on the stack is determined by the type of
exception. The reset exception causes the M68000 to halt current execution and to read a
new SSP and PC as shown in Table 2-5. A bus error or address error causes the M68000
to store the information shown in Figure 2-3. The interrupts, traps, illegal instructions, and
trace stack frames are shown in Figure 2-4.
MOTOROLA
NOTES:
1. Vector numbers 12–14, 16–23, and 48–63 are reserved for future enhancements by Motorola
2. Unlike the other vectors which only require two words, reset vector (0) requires four words and is
3. The spurious interrupt vector is taken when there is a bus error indication during interrupt
4. TRAP # n uses vector number 32 + n.
16–23 1
48–63 1
64–255
32–47
(with vectors 60–63 being used by the M68302 (see 2.7 MC68302 IMP Configuration and
Control)). No user peripheral devices should be assigned these numbers.
located in the supervisor program space.
processing.
12 1
13 1
14 1
11
15
24
25
26
27
28
29
30
31
Table 2-5. M68000 Exception Vector Assignment
1020
100
104
108
112
116
120
124
128
188
192
255
256
44
48
52
56
60
64
92
96
MC68302 USER’S MANUAL
0BC
0FC
3FC
02C
03C
05C
06C
07C
0C0
030
034
038
040
060
064
068
070
074
078
080
100
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
SD
Line 1111 Emulator
(Unassigned, Reserved)
(Unassigned, Reserved)
(Unassigned, Reserved)
Uninitialized Interrupt Vector
(Unassigned, Reserved)
Spurious Interrupt 3
Level 1 Interrupt Autovector
Level 2 Interrupt Autovector
Level 3 Interrupt Autovector
Level 4 Interrupt Autovector
Level 5 Interrupt Autovector
Level 6 Interrupt Autovector
Level 7 Interrupt Autovector
TRAP Instruction Vectors 4
(Unassigned, Reserved)
User Interrupt Vectors
MC68000/MC68008 Core
2-9