78
ATmega161(L)
1228B–09/01
Table 25.
UBR Settings at Various Crystal Frequencies in Double-speed Mode
Baud Rate
1.0000 MHz
% Error
1.8432 MHz
% Error
2.0000 MHz
% Error
2400
4800
9600
14400
19200
28800
38400
57600
76800
115200
230400
UBR =
51
UBR =
25
UBR =
12
UBR = 8
UBR = 6
UBR = 3
UBR = 2
UBR = 1
UBR = 1
UBR = 0
-
0.2
0.2
0.2
3.7
7.5
7.8
7.8
7.8
22.9
84.3
-
UBR =
95
UBR =
47
UBR =
23
UBR =
15
UBR =
11
UBR =
7
UBR =
5
UBR =
3
UBR =
2
UBR =
1
UBR =
0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
UBR =
103
UBR =
51
UBR =
25
UBR = 16
UBR =
12
UBR = 8
UBR = 6
UBR = 3
UBR = 2
UBR = 1
UBR = 0
0.2
0.2
0.2
2.1
0.2
3.7
7.5
7.8
7.8
7.8
84.3
Baud Rate
3.2768 MHz
% Error
3.6864 MHz
% Error
4.0000 MHz
% Error
2400
4800
9600
14400
19200
28800
38400
57600
76800
115200
230400
460800
912600
UBR =
170
UBR =
84
UBR =
42
UBR = 27
UBR = 20
UBR = 13
UBR = 10
UBR = 6
UBR = 4
UBR = 3
UBR = 1
UBR = 0
-
0.2
0.4
0.8
1.6
1.6
1.6
3.1
1.6
6.2
12.5
12.5
12.5
-
UBR =
191
UBR =
95
UBR =
47
UBR =
31
UBR =
23
UBR =
15
UBR =
11
UBR =
7
UBR =
5
UBR =
3
UBR =
1
UBR =
0
-
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
-
UBR =
207
UBR =
103
UBR =
51
UBR =
34
UBR =
25
UBR = 16
UBR =
12
UBR = 8
UBR = 6
UBR = 3
UBR = 1
UBR = 0
UBR = 0
0.2
0.2
0.2
0.8
0.2
2.1
0.2
3.7
7.5
7.8
7.8
7.8
84.3
Baud Rate
7.3728 MHz
% Error
8.0000 MHz
% Error
9.2160 MHz
% Error
2400
4800
9600
14400
19200
28800
38400
57600
76800
115200
230400
460800
912600
UBR =
383
UBR =
191
UBR =
95
UBR =
63
UBR =
47
UBR =
31
UBR =
23
UBR =
15
UBR =
11
UBR =
7
UBR =
3
UBR =
1
UBR =
0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
UBR =
416
UBR =
207
UBR =
103
UBR =
68
UBR =
51
UBR =
34
UBR =
25
UBR = 16
UBR = 12
UBR = 8
UBR = 3
UBR = 1
UBR = 0
0.1
0.2
0.2
0.6
0.2
0.8
0.2
2.1
0.2
3.7
7.8
7.8
7.8
UBR =
479
UBR =
239
UBR =
119
UBR =
79
UBR =
59
UBR =
39
UBR =
29
UBR =
19
UBR =
14
UBR =
9
UBR =
4
UBR = 2
UBR = 0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
20.0
20.0