upd70f3422gj-gae-qs-ax Renesas Electronics Corporation., upd70f3422gj-gae-qs-ax Datasheet - Page 532

• Manufacturer Part Number: upd70f3422gj-gae-qs-ax
• Description: 32-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

Chapter 16
532
Internal signal A
Internal signal B
Internal signal C
Base clock (f
RXDAn (input)
Base clock
Figure 16-10
Figure 16-9
RXDAn
16.5.10 Receive data noise filter
UCLK
)
In
This filter samples the RXDAn pin using the base clock of the prescaler output.
When the same sampling value is read twice, the match detector output
changes and the RXDAn signal is sampled as the input data. Therefore, data
not exceeding 2 clock width is judged to be noise and is not delivered to the
internal circuit (see Figure 16-10). See “Base clock“ on page 533 regarding the
base clock.
Moreover, since the circuit is as shown in Figure 16-9, the processing that
goes on within the receive operation is delayed by 3 clocks in relation to the
external signal status.
Noise filter circuit
Timing of RXDAn signal judged as noise
Preliminary User’s Manual U17566EE1V2UM00
Q
Internal signal A
Match
In
(judged as noise)
Q
Mismatch
Internal signal B
Asynchronous Serial Interface (UARTA)
detector
Match
Match
In
LD_EN
Q
(judged as noise)
Internal signal C
Mismatch