Table 107. Examples of UBRRn Settings for Commonly Used Oscillator Frequencies (Continued)
fosc = 3.6864 MHz
U2Xn = 0
fosc = 4.0000 MHz
U2Xn = 0
fosc = 7.3728 MHz
U2Xn = 0
Baud
Rate
(bps)
U2Xn = 1
UBRR Error
U2Xn = 1
UBRR Error
U2Xn = 1
UBRR Error
UBRR
Error
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
-7.8ꢀ
–
UBRR
Error
0.2ꢀ
0.2ꢀ
0.2ꢀ
2.1ꢀ
0.2ꢀ
-3.5ꢀ
-7.0ꢀ
8.5ꢀ
8.5ꢀ
8.5ꢀ
8.5ꢀ
0.0ꢀ
–
UBRR
Error
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
-7.8ꢀ
-7.8ꢀ
–
2400
4800
9600
14.4k
19.2k
28.8k
38.4k
57.6k
76.8k
115.2k
230.4k
250k
95
47
23
15
11
7
191
95
47
31
23
15
11
7
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
-7.8ꢀ
-7.8ꢀ
–
103
51
25
16
12
8
207
103
51
34
25
16
12
8
0.2ꢀ
0.2ꢀ
0.2ꢀ
-0.8ꢀ
0.2ꢀ
2.1ꢀ
0.2ꢀ
-3.5ꢀ
-7.0ꢀ
8.5ꢀ
8.5ꢀ
0.0ꢀ
0.0ꢀ
–
191
95
47
31
23
15
11
7
383
191
95
63
47
31
23
15
11
7
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
0.0ꢀ
-7.8ꢀ
-7.8ꢀ
-7.8ꢀ
5
6
3
3
2
5
2
6
5
1
3
1
3
3
0
1
0
1
1
3
0
1
0
1
1
3
0.5M
1M
–
0
–
0
0
1
–
–
–
–
–
–
–
0
Max. (1)
230.4 kbps
UBRR = 0, Error = 0.0ꢀ
460.8 kbps
250 kbps
0.5 Mbps
460.8 kbps
921.6 kbps
1.
228
ATmega640/1280/1281/2560/2561
2549A–AVR–03/05