
APPENDIX
Appendix 6. Q & A
7702/7703 Group User’s Manual
21–48
Interrupt
To prevent this problem, use software to execute the routine that should not accept a certain interrupt
request after change of interrupt priority level is completed. The following shows a sample program.
[ Sample program ]
After an instruction which writes “0002” to the interrupt priority level select bits, fill the instruc-
tion queue buffer with the NOP instruction to make the next instruction not be executed before the
writing is completed.
:
CLB #07H, XXXIC ; Sets the interrupt priority level select bits to “0002.”
NOP
;
NOP
;
NOP
;
LDA A,DATA
; Instruction at the beginning of the routine that should not accept a certain
interrupt request
(2/2)
A