Motorola MC68020 User Manual page 153

Stack Frames
15
SP STATUS REGISTER
+$02
PROGRAM COUNTER
+$06 0 0 0 0
FOUR-WORD STACK FRAME — FORMAT $0
15
SP
STATUS REGISTER
+$02
PROGRAM COUNTER
+$06 0 0 0 1
THROWAWAY FOUR-WORD
STACK FRAME — FORMAT $1
15
SP STATUS REGISTER
+$02
PROGRAM COUNTER
+$06
0 0 1 0
+$08
INSTRUCTION ADDRESS
STACK FRAME — FORMAT $2
15
SP
STATUS REGISTER
+$02
PROGRAM COUNTER
+$06 1 0 0 1
+$08 INSTRUCTION ADDRESS
+$0C
INTERNAL REGISTERS,
+$12
COPROCESSOR MIDINSTRUCTION
STACK FRAME (10 WORDS) — FORMAT $9
MOTOROLA
Table 6-5. Exception Stack Frames
0
VECTOR OFFSET
0
VECTOR OFFSET
0
VECTOR OFFSET
SIX-WORD
0
VECTOR OFFSET
4 WORDS
M68020 USER'S MANUAL
Exception Types (Stacked PC Points to)
Interrupt [Next instruction]
Format Error [RTE or cpRESTORE instruction
TRAP #N [NEXT instruction]
Illegal Instruction [Illegal instruction]
A-Line Instruction [A-line instruction]
F-Line Instruction [F-line instruction]
Privilege Violation [First word of instruction causing
Privilege Violation]
Coprocessor [Opword of instruction that
Preinstruction returned the 'take preinstruction'
primitive]
Created on [Next instruction — same as on
Interrupt Stack master stack]
during interrupt
exception processing
when transition from
master state to
interrupt state occurs
[Next instruction for all these
CHK
exceptions]
CHK2
cpTRAPcc
INSTRUCTION ADDRESS
TRAPcc
is the address of the instruction
TRAPPV
that caused the exception
Trace
Zero Divide
MMU Configuration
Coprocessor
Postinstruction
[Next word to be fetched from
Coprocessor
instruction stream for all these
Midinstruction
exceptions]
Main-Detected
Protocol Violation
INSTRUCTION ADDRESS
Interrupt Detected
is the address of the instruction
During Coprocessor
that caused the exception
Instruction
(supported with 'null
come again with
interrupts allowed'
primitive)
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