Datasheet

230
2549O–AVR–05/12
ATmega640/1280/1281/2560/2561
Note: 1. UBRR = 0, Error = 0.0%
Table 22-11. Examples of UBRRn Settings for Commonly Used Oscillator Frequencies
Baud
Rate
(bps)
f
osc
= 8.0000MHz f
osc
= 11.0592MHz f
osc
= 14.7456MHz
U2Xn = 0 U2Xn = 1 U2Xn = 0 U2Xn = 1 U2Xn = 0 U2Xn = 1
UBRR Error UBRR Error UBRR Error UBRR Error UBRR Error UBRR Error
2400 207 0.2% 416 -0.1% 287 0.0% 575 0.0% 383 0.0% 767 0.0%
4800 103 0.2% 207 0.2% 143 0.0% 287 0.0% 191 0.0% 383 0.0%
9600 51 0.2% 103 0.2% 71 0.0% 143 0.0% 95 0.0% 191 0.0%
14.4K 34 -0.8% 68 0.6% 47 0.0% 95 0.0% 63 0.0% 127 0.0%
19.2K250.2%510.2%350.0%710.0%470.0%950.0%
28.8K 16 2.1% 34 -0.8% 23 0.0% 47 0.0% 31 0.0% 63 0.0%
38.4K120.2%250.2%170.0%350.0%230.0%470.0%
57.6K 8 -3.5% 16 2.1% 11 0.0% 23 0.0% 15 0.0% 31 0.0%
76.8K 6 -7.0% 12 0.2% 8 0.0% 17 0.0% 11 0.0% 23 0.0%
115.2K 3 8.5% 8 -3.5% 5 0.0% 11 0.0% 7 0.0% 15 0.0%
230.4K 1 8.5% 3 8.5% 2 0.0% 5 0.0% 3 0.0% 7 0.0%
250K 1 0.0% 3 0.0% 2 -7.8% 5 -7.8% 3 -7.8% 6 5.3%
0.5M 0 0.0% 1 0.0% – – 2 -7.8% 1 -7.8% 3 -7.8%
1M––00.0%––––0-7.8%1-7.8%
Max.
(1)
0.5Mbps 1Mbps 691.2Kbps 1.3824Mbps 921.6Kbps 1.8432Mbps