Motorola MC68VZ328 - Manual (Page 153)

Exception Vectors
Interrupt Controller 9-3
programmable, but the lower 3 bits reflect the interrupt level that is being serviced. All interrupts are
maskable. Writing a 1 to a bit in the interrupt mask register disables that interrupt. If an interrupt is
masked, you can find out its status in the interrupt pending register.
9.2 Exception Vectors
A vector number is an 8-bit number that can be multiplied by four to obtain the address of an exception
vector. An exception vector is the memory location from which the processor fetches the address of a
software routine that is used to handle an exception. Each exception has a vector number and an exception
vector, as described in Table 9-1. User interrupts are part of the exception processing on the MC68VZ328,
and the vector numbers for user interrupts are configurable. For additional information regarding exception
processing, see the M68000 Family Programmer’s Reference Manual.
Table 9-1. Exception Vector Assignment
Vector Number Address Number
Space
1 Assignment
Hex Decimal Decimal Hex
0 0 0 000 SP
Reset: initial SSP 2
1 1 4 004 SP Reset: initial PC
2 2 8 008 SD Bus error
3 3 12 00C SD Address error
4 4 16 010 SD Illegal instruction
5 5 20 014 SD Divide-by-zero
6 6 24 018 SD CHK instruction
7 7 28 01C SD TRAPV instruction
8 8 32 020 SD Privilege violation
9 9 36 024 SD Trace
A 10 40 028 SD Line 1010 emulator
B 11 44 02C SD Line 1111 emulator
C 12 48 030 SD
Unassigned, reserved
3
D 13 52 034 SD
Unassigned, reserved 3
E 14 56 038 SD
Unassigned, reserved
3
F 15 60 03C SD Uninitialized interrupt vector
10–17 16–23 64–92 040–05C SD
Unassigned, reserved
3
18 24 96 060 SD Spurious interrupt 4
19 25 100 064 SD Level 1 interrupt autovector