CHAPTER 7 INTERRUPT AND TEST FUNCTIONS
211
User��s Manual U10676EJ3V0UM
(7) Enabling nesting of two interrupts - INTT0 and INT0 are nested doubly and INTBT and INTT2 are nestedsingly -
Reset
INTBT
<1>
EI
EI
EI
EI
EI
IET0
IE0
IEBT
IET2
Status 0
Status 0
<lNTBT servicing program>
Status 0
Status 1
INTT0
<3>
RETI
<4>
Status 1
Status 0
EI
EI
RETI
<5> IEBT
IET2
DI
CLR1
DI
DI
EI
<2>
IST0
IEBT
IET2
<lNTT0 servicing program>
<Main program>
<1> When an INTBT that does not enable nesting occurs, the INTBT servicing routine is started. The statusis 1.<2> The status is changed to 0 by clearing IST0. INTBT and INTT2 that do not enable nesting are disabled.<3> When an INTT0 that enables nesting occurs, nesting is executed. The status is changed to 1, and allinterrupts are disabled.<4> The status is returned to 1 when INTT0 servicing is completed.<5> The disabled INTBT and INTT2 are enabled, and execution returns to the main routine.