h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 507

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Thus the receive margin in asynchronous mode is given by equation (1) below.
Where M: Receive margin (%)
Assuming values of F = 0 and D = 0.5 in equation (1), a receive margin of 46.875% is given by
equation (2) below.
When D = 0.5 and F = 0,
However, this is only a theoretical value, and a margin of 20% to 30% should be allowed in
system design.
Internal base
clock
Receive data
(RxD)
Synchronization
sampling timing
Data sampling
timing
N: Ratio of bit rate to clock (N = 16)
D: Clock duty (D = 0 to 1.0)
L: Frame length (L = 9 to 12)
F: Absolute value of clock rate deviation
M = 0.5 –
M =
= 46.875%
Figure 15.23 Receive Data Sampling Timing in Asynchronous Mode
0.5 –
0
2
2N
1
1
8 clocks
16
Start bit
– (L – 0.5)F –
100%
16 clocks
7
D – 0.5
N
Section 15 Serial Communication Interface (SCI, IrDA)
(1 + F)
15 0
Rev. 4.00 Jun 06, 2006 page 453 of 1004
100%
D0
7
.......... (1)
.......... (2)
REJ09B0301-0400
15 0
D1