NEC uPD78P078 - Manual (Page 511)

511
CHAPTER 22 INTERRUPT FUNCTIONS
t SMP
Sampling Clock
INTP0
PIF0 “L”
Because INTP0 level is not active in sampling,
PIF0 output remains at low level.
When the setting INTP0 input level is active twice in succession, the noise eliminator sets interrupt request
flag (PIF0) to 1.
Figure 22-8 shows the noise eliminator input/output timing.
Figure 22-8. Noise Eliminator Input/Output Timing (during Rising Edge Detection)
(a) When input is less than the sampling cycle (t
SMP
)
(b) When input is equal to or twice the sampling cycle (t
SMP
)
(c) When input is twice or more than the cycle frequency (t SMP )
t SMP
Sampling Clock
INTP0
PIF0
Because sampling INTP0 level is active twice in succession in <2>,
PIF0 flag is set to 1.
<1> <2>
t
SMP
Sampling Clock
INTP0
PIF0
When INTP0 level is active twice in succession,
PIF0 flag is set to 1.