Interrupt Exception Processing Flowchart - Motorola MC68020 User Manual

EXIT
THESE
INDIVIDUAL
BUS CYCLES
MAY OCCUR
IN ANY ORDER
* Does not apply to the MC68EC020.
Figure 6-5. Interrupt Exception Processing Flowchart
6-16
ONCE PER INSTRUCTION
AT INSTRUCTION
BOUNDARY
OTHERWISE
* IPEND ASSERTED
* NEGATE IPEND
EXECUTE INTERRUPT
ACKNOWLEDGE CYCLE
SR
TEMP
1
S
0
T1, T0
UPDATE I2–I0
– (SP) TEMP
– (SP) PC
– (SP) FORMAT WORD
– (SP) OTHER EXCEPTION
DEPENDENT INFORMATION
M = 0
PC VECTOR TABLE ENTRY
PREFETCH 3 WORDS
END OF EXCEPTION PROCESSING
FOR THE INTERRUPT
M68020 USER'S MANUAL
M = 1
TEMP SR
M 0
BEGIN EXECUTION OF THE INTERRUPT
HANDLER ROUTINE OR PROCESS A
HIGHER PRIORITY EXCEPTION
MOTOROLA