UPD78F0411GA-GAM-AX Datasheet, PDF (422/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 16 MANCHESTER CODE GENERATOR
<2> Error of baud rate
The baud rate error can be calculated by the following expression.
Actual baud rate (baud rate with error)
• Error (%) =
− 1 × 100 [%]
Desired baud rate (correct baud rate)
Caution Keep the baud rate error during transmission to within the permissible error range at the
reception destination.
Example: Frequency of base clock = 2.5 MHz = 2,500,000 Hz
Set value of MC0BRS4 to MC0BRS0 bits of MC0CTL2 register = 10000B (k = 16)
Target baud rate = 76,800 bps
Baud rate = 2.5 M/(2 × 16)
= 2,500,000/(2 × 16) = 78125 [bps]
Error = (78,125/76,800 − 1) × 100
= 1.725 [%]
<3> Example of setting baud rate
Baud
Rate
[bps]
fPRS = 10.0 MHz
fPRS = 8.38 MHz
fPRS = 8.0 MHz
fPRS = 6.0 MHz
MC0CKS2 k Calculated ERR MC0CKS2 k Calculated ERR MC0CKS2 k Calculated ERR MC0CKS2 k Calculated ERR
to
Value [%]
to
Value [%]
to
Value [%]
to
Value [%]
MC0CKS0
MC0CKS0
MC0CKS0
MC0CKS0
4800
–
–
–
– 5, 6, or 7 27 4850 1.03 5, 6, or 7 26 4808 0.16 5, 6, or 7 20 4688 –2.34
9600 5, 6, or 7 16 9766 1.73
4
27 9699 1.03 5, 6, or 7 13 9615 0.16
4
20 9375 –2.34
19200
5
8 19531 1.73
3
27 19398 1.03
4
13 19231 0.16
4
10 18750 –2.34
31250
4
10 31250 0
2
17 30809 –1.41
4
8 31250 0
2
24 31250 0
38400
4
8 39063 1.73
2
27 38796 1.03
3
13 38462 0.16
2
20 37500 –2.34
56000
3
11 56818 1.46
2
19 55132 –1.55
3
9 55556 –0.79
1
27 55556 –0.79
62500
2
20 62500 0
2
17 61618 –1.41
3
8 62500 0
2
12 62500 0
76800
2
16 78125 1.73
1
27 77592 1.03
2
13 76923 0.16
2
10 75000 –2.34
115200
1
22 113636 –1.36
2
9 116389 1.03
1
17 117647 2.12
1
13 115385 0.16
125000
1
20 125000 0
1
17 123235 –1.41
1
16 125000 0
1
12 125000 0
153600
1
16 156250 1.73
2
7 149643 –2.58
1
13 153846 0.16
1
10 150000 –2.34
250000
1
10 250000 0
1
8 261875 4.75
1
8 250000 0
1
6 250000 0
0
17 246471 –1.41
Remark
MC0CKS2 to MC0CKS0: Bits 2 to 0 of MCG control register 1 (MC0CTL1) (setting of base clock (fXCLK))
k:
Value set by bits 4 to 0 (MC0BRS4 to MC0BRS0) of MCG control register 2
(MC0CTL2) (k = 4, 5, 6, …, 31)
fPRS:
Peripheral hardware clock frequency
ERR:
Baud rate error
420
User’s Manual U18698EJ1V0UD