HD6412373R RENESAS [Renesas Technology Corp], HD6412373R Datasheet - Page 819

• Manufacturer Part Number: HD6412373R
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

falling edge of the start bit using the basic clock, and performs internal synchronization. As shown
in figure 15.25, by sampling receive data at the rising-edge of the 16th, 32nd, 186th, or 128th
pulse of the basic clock, data can be latched at the middle of the bit. The reception margin is given
by the following formula.
Where M: Reception margin (%)
Assuming values of F = 0, D = 0.5 and N = 372 in the above formula, the reception margin
formula is as follows.
Internal
basic clock
Receive data
(RxD)
Synchronization
sampling timing
Data sampling
timing
M = ⏐ (0.5 –
N: Ratio of bit rate to clock (N = 32, 64, 372, and 256)
D: Clock duty cycle (D = 0 to 1.0)
L: Frame length (L = 10)
F: Absolute value of clock frequency deviation
M = (0.5 – 1/2 × 372) × 100%
= 49.866%
Figure 15.25 Receive Data Sampling Timing in Smart Card Mode
2N
1
186 clocks
0
) – (L – 0.5) F –
(Using Clock of 372 Times the Bit Rate)
185
372 clocks
Start bit
371
Section 15 Serial Communication Interface (SCI, IrDA)
⏐D – 0.5⏐
0
N
D0
Rev.7.00 Mar. 18, 2009 page 751 of 1136
(1 + F) ⏐ × 100 [%]
185
371 0
REJ09B0109-0700
D1