Datasheet

Section 13 Serial Communication Interface
REJ09B0140-0900 Rev. 9.00 Page 405 of 846
Sep 16, 2010
H8S/2215 Group
12345678910 12345678
11 12 13 14 15 16 17 18 19 20 21 2322
12345678
24 25 1 2 5 6 7 8 9 10
12
11 12 13
34
14 15 16 17 19
567
18
8
20 21 22 23 24
1234
2534
8 MHz
Base clock
16 MHz/2 = 8 MHz
8 MHz × (47/51) = 7.3725 MHz
(average)
7.3725 MHz
1 bit = base clock × 16*
1234567891011121314151617 123456789101112 13141516
18 19 20 21 2322 24 25 26 27 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 1
1 2 3 4 5 6 7 8 9 101112131415 16 1 2 3 4 5 6 7 8 9 101112131415 16
234567828 29
8 MHz
Base clock
16 MHz/2 = 8 MHz
8 MHz × (18/25) = 5.76 MHz
(average)
Base clock with 460.784 kbps average transfer rate (ACS2 to 0 = B'110)
Average transfer rate = 7.3725 MHz/16 = 460.784 kbps Average error = -0.004% Average transfer rate = 5.76 MHz/8 = 720 kbps Average error = ±0%
Base clock with 720 kbps average transfer rate (ACS2 to 0 = B'111)
5.76 MHz
1 bit = base clock × 8*
12 345 6 7 8
123
2 MHz
1.8431 MHz
1 bit = base clock × 16*
Base clock
16 MHz/8 = 2 MHz
2
MHz × (47/51) = 1.8431 MHz
(average)
4567891011121314151617
123456789101112 13141516
26 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 1 2 3 4 5 6 7 8
1234567 1234567
18 19 20 21 2322 24 25 27 30 31 32 33 3428 29
1234 65 7 8 9 12 13 14 15 1610 11 1234 65 7 8 9 12 13 14 15 1610 11
When φ = 16 MHz Base clock with 115.196 kbps average transfer rate (ACS2 to 0 = B'101)
Average transfer rate = 1.8431 MHz/16 = 115.196 kbps Average error = -0.004%
Note:
*
As the base clock synchronization varies, so does the length of one bit.
Figure 13.4 Examples of Base Clock when Average Transfer Rate Is Selected (1)