M37702E6BFS Renesas Electronics America, M37702E6BFS Datasheet - Page 492

• Manufacturer Part Number: M37702E6BFS
• Description: EPROM MCU/8BIT CMOS EMULATION CH
• Manufacturer: Renesas Electronics America

Specifications of M37702E6BFS

• Accessory Type: Emulator EPROM MCU
• For Use With/related Products: 7702
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPENDIX
Appendix 6. Q & A
21–46
If an interrupt request (b) occurs while executing an interrupt routine (a), is the main routine is not
executed before the INTACK sequence for the next interrupt (b) is executed after the interrupt routine
(a) under execution is completed?
Sampling for interrupt requests are performed by sampling pulses generated synchronously with the
CPU’s op-code fetch cycles.
(1) If the next interrupt request (b) occurs before the sampling pulse ( ) for the RTI instruction is
Condition
(2) If the next interrupt request (b) occurs immediately after generating of the sampling pulse
Q
A
I is cleared to “0” with the RTI instruction.
The interrupt priority level of the interrupt (b) is higher than the main routine IPL.
The interrupt priority detection time is 2 cycles of
generated, the microcomputer executes the INTACK sequence for (b) without executing the main
routine (not even one instruction) because sampling is completed while executing the RTI
instruction.
microcomputer executes one instruction of the main routine before executing the INTACK se-
quence for (b) because the interrupt request is sampled by the next sampling pulse
Sampling pulse
Sampling pulse
Sequence of
execution
Interrupt routine (a)
RTI instruction
Interrupt routine (a)
Interrupt routine (a)
Interrupt request (b)
RTI instruction
RTI instruction
7702/7703 Group User’s Manual
Interrupt request (b)
Main routine
?
One instruction executed
Main routine
INTACK sequence for interrupt (b)
INTACK sequence
for interrupt (b)
INTACK sequence
for interrupt (b)
.
Interrupt
, the