NEC PD78F9488 - Manual (Page 288)

CHAPTER 15 REMOTE CONTROLLER RECEIVER ( µ PD789489, 78F9489 ONLY)
User’s Manual U15331EJ4V1UD
288
Figure 15-8. Noise Elimination Operation Example (1/2)
(a) 1-clock noise elimination (PRSEN = 0, NCW = 0)
Remark Internal RIN is a signal after synchronization and sampling are performed twice, and is therefore later
than the actual signal input from the outside to the RIN pin by two to three clocks.
(b) 2-clock noise elimination (PRSEN = 0, NCW = 1)
Remark Internal RIN is a signal after synchronization and sampling are performed three times, and is therefore
later than the actual signal input from the outside to the RIN pin by 3 to 4 clocks.
Clock
Clock RIN (ideal)
RIN
Synchronization
samp2
samp3
Internal RIN
Noise
Delayed by 3 to 4 clocks
samp1
H
H
L
H
L
L
L
Since synchronized signal = samp1 = H, samp1 is latched from this
point and later.
Since synchronized signal = samp2 = H is not satisfied, samp2 is
not latched.
Clock
RIN (ideal)
RIN
Synchronization
samp1
samp2
Internal RIN
Noise
Delayed by 2 to 3 clocks
L
H
L
L
Since synchronized signal = samp1 = H is not satisfied, samp1 is not latched.
L