SN8F2280 Series
USB 2.0 Full-Speed 8-Bit Micro-Controller
10.5 UART BAUD RATE CONTROL REGISTER
URBRC initial value =11010101
0ABH
URBRC
Read/Write
After Reset
Bit 7
UDIV4
R/W
1
Bit 6
UDIV3
R/W
1
Bit 5
UDIV2
R/W
0
Bit 4
UDIV1
R/W
1
Bit 3
UDIV0
R/W
0
Bit 2
UPCS2
R/W
1
Bit 1
UPCS1
R/W
0
Bit 0
UPCS0
R/W
1
Bit[7:3]
Bit[2:0]
UDIV[4:0]: UART baud rate divider.
UPCS[2:0]: UART baud rate pre-scalar.
The UART baud rate clock source is Fhosc and divided by pre-scalar and divider. The equation is as following.
UART Baud Rate = (Fhosc / 2PreScalar / (Divider+1)) / 16 ∈ Divider≠0
UART Clock Source =
16MHz (UCLKS = 0)
UART Clock Source =
24MHz (UCLKS = 1)
Baud Rate
UPCS[2:0]
101
UDIV[4:0]
11010
11010
11010
11010
11001
11001
10011
10000
01001
-
UPCS[2:0]
UDIV[4:0]
1200
2400
-
-
100
-
-
4800
011
-
-
9600
010
-
-
19200
38400
51200
57600
102400
115200
001
-
-
000
-
-
000
-
-
-
000
-
-
000
-
-
000
01100
SONiX TECHNOLOGY CO., LTD
Page 120
Version 1.1
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