MC68020 Motorola, MC68020 Datasheet - Page 144

• Manufacturer Part Number: MC68020
• Description: (MC68020 / MC68EC020) MICROPROCESSORS USERS MANUAL
• Manufacturer: Motorola

MOTOROLA
Priority
NOTE: 0.0 is the highest priority; 4.2 is the lowest.
Group/
0
1
2
3
4
0.0—Reset
1.0—Address Error
1.1—Bus Error
2.0—BKPT, CALLM, CHK, CHK2,
3.0—Illegal Instruction, Line A, Unimplemented
4.0—cp Postinstruction
4.1—Trace
4.2—Interrupt
PIPE STAGE D
cp Midinstruction, cp Protocol Violation,
cpTRAPcc, Divide by Zero, RTE, RTM,
TRAP, TRAPcc, TRAPV
Line F, Privilege Violation, cp Preinstruction
Exception and Relative Priority
EXECUTE INSTRUCTION WORD
Figure 6-6. Breakpoint Instruction Flowchart
INSTRUCTION WORD ON DATA BUS
Table 6-4. Exception Priority Groups
EXIT
CYCLE TERMINATED WITH
DSACK1/DSACK0
M68020 USER’S MANUAL
A4–A2
INITIATE READ BUS CYCLE
A19–A16
BREAKPOINT NUMBER
ENTRY
Aborts all processing (instruction or exception) and
does not save old context.
Suspends processing (instruction or exception) and
saves internal context.
Exception processing is part of instruction execution.
Exception processing begins before instruction is
executed.
Exception processing begins when current instruction
or previous exception processing has completed.
$0
CYCLE TERMINATED WITH
BERR
TAKE ILLEGAL INSTRUCTION
Characteristic
EXCEPTION
6- 19