HD64F2638F20J Datasheet, PDF (592/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 14 Smart Card Interface
H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
Thus the reception margin in asynchronous mode is given by the following formula.
Formula for reception margin in smart card interface mode
1
⎥ D – 0.5⎥
M =⎥ (0.5 –
) – (L – 0.5) F –
(1 + F)⎥ × 100%
2N
N
Where M: Reception margin (%)
N: Ratio of bit rate to clock (N = 32, 64, 372, and 256)
D: Clock duty (D = 0 to 1.0)
L: Frame length (L = 10)
F: Absolute value of clock frequency deviation
Assuming values of F = 0, D = 0.5 and N = 372 in the above formula, the reception margin
formula is as follows.
When D = 0.5 and F = 0,
M = (0.5 – 1/2 × 372) × 100%
= 49.866%
Page 542 of 1458
REJ09B0103-0800 Rev. 8.00
May 28, 2010