NEC PD78F9488 - Manual (Page 289)

CHAPTER 15 REMOTE CONTROLLER RECEIVER ( µ PD789489, 78F9489 ONLY)
User’s Manual U15331EJ4V1UD
289
Figure 15-8. Noise Elimination Operation Example (2/2)
(c) 2-clock noise elimination (PRSEN = 1, 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 4 to 6 clocks.
(d) 4-clock noise elimination (PRSEN = 1, 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 6 to 8 clocks.
Clock divider
RIN (ideal)
RIN
Synchronization
samp2
samp3
Internal RIN
Noise
Delayed by 6 to 8 clocks
samp1
Clock
H
H
L
H
L
L
Since synchronized signal = samp2 = H
is not satisfied, samp2 is not latched.
Since synchronized signal =
samp1 = H, samp1 is
latched.
L
Clock divider
RIN (ideal)
RIN
Synchronization
samp2
Internal RIN
Noise
Delayed by 4 to 6 clocks
samp1
Clock
L
H
L
L
Since synchronized signal = samp1 = H is not satisfied, samp1 is
not latched.
L