SH79F6488PSLASH080PR datasheet(98/152 Pages) SINOWEALTH

98 / 152 page

SH79F6488/SH79F6489

8.5.3 Baud Rate Generate

The baud rate generator is an 15-bit up-counting timer

15-bit timer

To EUART

Overflow

Fsys

From 7FFFH to 0000H

SBRTH[14:8],SBRTL7:0]

Baudrate Generator for EUART

SBRTEN=1

SBRT

32768

Fsys

owrate

SBRToverfl

−

SBRTL]

[SBRTH,

SBRT

In Mode0, the baud rate is programmable to either 1/12 or 1/4 of the system frequency. This baud rate is determined by SM2 bit.

When set to 0, the serial port runs at 1/12 of the system clock. When set to 1, the serial port runs at 1/4 of the system clock.

In Mode1 & Mode3, the baud rate can be fine adjusted.

The Mode1 & 3 baud rate equations are shown below,

(

) BFINE

SBRT

32768

Fsys

BaudRate

For example: Fsys = 8MHz, to get 115200Hz baud rate, computing method of SBRT and SFINE as shown below:

8000000/16/115200 = 4.34

SBRT = 32768 - 4 = 32764

115200 = 8000000/(16 X 4 + BFINE)

BFINE = 5.4 ≈ 5

This fine tuning method to calculate the actual baud rate is 115942Hz and the error is 0.64%, but the error is 8.5% In the past

computing method.

In Mode2, the baud rate is programmable to either 1/32 or 1/64 of the system clock. This baud rate is determined by the SMOD

bit (PCON.7). When this bit is set to 0, the serial port runs at 1/64 of the clock. When set to 1, the serial port runs at 1/32 of the

clock.

)

(

BaudRate

SYS

SMOD

SH79F6488P/080PR Datasheet(PDF) 98 Page - SINOWEALTH Electronic Ltd

SH79F6488P/080PR Datasheet(HTML) 98 Page - SINOWEALTH Electronic Ltd

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL