TC35679FSG-002

2018-01-17

18

4.3.5.

UART Baud Rate Setting

TC35679 UART interface has a programmable baud rate setting function. The UART baud rate is generated from 26 MHz clock,

and can be set according to the following equation depending on over sampling number and dividing ratio.

Ratio

Dividing

Number

Sampling

Over

Frequency

Clock

Generating

Rate

Baud

BaudRate

UART

×

=

　

　

Table 4-2 shows examples of UART Baud rate settings. If other target baud rates are required, please contact our engineering

department.

Table 4-2 UART Baud rate settings

Target baud rate

[bps]

Actual baud rate

[bps]

Over sampling rate

Frequency

dividing ratio

9600

9587.021

12

226

14400

14396.46

14

129

19200

19174.04

12

113

28800

28856.83

17

53

38400

38461.54

13

52

57600

57777.78

15

30

76800

76923.08

13

26

115200

115555.6

15

15

153600

153846.15

13

13

230400

232142.9

16

7

307200

305882.4

17

5

460800

464285.7

14

4

921600

928571.4

14

2

Note: Error of target baud rate and the actual baud rate is to be set to within 1 %.

4.3.6.

TX message spacing function

TC35679 spaces more than 12 time frames between different TX messages making less than 12 time frames between TX frames

in a TX message when several TX frames belong to one TX message. Host CPU is able to know the boundaries between TX

messages by measuring time frames between TX frames.

Figure 4-8 TX frames and TX messages

UART TX data

UART TX massage

UART TX message

< 12 time frames

< 12 time frames

< 12 time frames

> 12 time frames

1 time frame