mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 1115

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

The
UART baud rate = UART module clock / (16 × (SBR[12:0] + BRFD))
The following table lists some examples of achieving target baud rates with a module
clock frequency of 10.2 MHz, with and without fractional fine adjustment.
Freescale Semiconductor, Inc.
(decimal)
Table 43-101
1062
2125
4250
5795
SBR
Bits
133
266
531
17
16
33
33
66
Table 43-101. Baud rates (example: module clock = 10.2 MHz)
0 0 0 0 0
0 0 0 0 1
0 0 0 1 0
0 0 0 1 1
0 0 1 0 0
0 0 1 0 1
0 0 1 1 0
0 0 1 1 1
0 1 0 0 0
0 1 0 0 1
0 1 0 1 0
0 1 0 1 1
0 1 1 0 0
BRFA
00000
10011
00000
00110
00000
00000
00000
00000
00000
00000
00000
00000
BRFA
Bits
lists the available baud divisor fine adjust values.
MCF51JF128 Reference Manual, Rev. 2, 03/2011
19/32=0.59375
Table 43-102. Baud rate fine adjust
6/32=0.1875
BRFD value
0
0
0
0
0
0
0
0
0
0
Table continues on the next page...
Chapter 43 Universal Asynchronous Receiver/Transmitter (UART)
Preliminary
clock (Hz)
600,000.0
614,689.3
309,090.9
307,344.6
154,545.5
Receiver
76,691.7
38,345.9
19,209.0
9604.5
4800.0
2400.0
1760.1
Baud Rate Fractional Divisor (BRFD)
Transmitter
11/32 = 0.34375
clock (Hz)
38,418.08
19,209.04
1/32 = 0.03125
3/32 = 0.09375
5/32 = 0.15625
7/32 = 0.21875
9/32 = 0.28125
10/32 = 0.3125
37,500.0
19,318.2
2/32 = 0.0625
6/32 = 0.1875
12/32 = 0.375
4/32 = 0.125
9659.1
4793.2
2396.6
1200.6
8/32 = 0.25
600.3
300.0
150.0
110.0
0/32 = 0
Target Baud
38,400
38,400
19,200
19,200
9600
4800
2400
1200
rate
600
300
150
110
0.047
0.047
Error
0.62
0.62
0.14
0.14
0.11
0.05
0.00
0.00
0.00
(%)
2.3
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