Datasheet

ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
166
Table 17-10. Examples of UBRRn Settings for Commonly Used Oscillator Frequencies (Continued)
Baud
Rate
(bps)
f
osc
= 3.6864MHz f
osc
= 4.0000MHz f
osc
= 7.3728MHz
U2Xn = 0 U2Xn = 1 U2Xn = 0 U2Xn = 1 U2Xn = 0 U2Xn = 1
UBRRn Error UBRRn Error UBRRn Error UBRRn Error UBRRn Error UBRRn Error
2400 95 0.0% 191 0.0% 103 0.2% 207 0.2% 191 0.0% 383 0.0%
4800 47 0.0% 95 0.0% 51 0.2% 103 0.2% 95 0.0% 191 0.0%
9600 23 0.0% 47 0.0% 25 0.2% 51 0.2% 47 0.0% 95 0.0%
14.4k 15 0.0% 31 0.0% 16 2.1% 34 –0.8% 31 0.0% 63 0.0%
19.2k 11 0.0% 23 0.0% 12 0.2% 25 0.2% 23 0.0% 47 0.0%
28.8k 7 0.0% 15 0.0% 8 –3.5% 16 2.1% 15 0.0% 31 0.0%
38.4k 5 0.0% 11 0.0% 6 –7.0% 12 0.2% 11 0.0% 23 0.0%
57.6k 3 0.0% 7 0.0% 3 8.5% 8 –3.5% 7 0.0% 15 0.0%
76.8k 2 0.0% 5 0.0% 2 8.5% 6 –7.0% 5 0.0% 11 0.0%
115.2k 1 0.0% 3 0.0% 1 8.5% 3 8.5% 3 0.0% 7 0.0%
230.4k 0 0.0% 1 0.0% 0 8.5% 1 8.5% 1 0.0% 3 0.0%
250k 0 –7.8% 1 –7.8% 0 0.0% 1 0.0% 1 –7.8% 3 –7.8%
0.5M – – 0 –7.8% – – 0 0.0% 0 –7.8% 1 –7.8%
1M – – – – – – – – – – 0 –7.8%
Max.
(1)
230.4kbps 460.8kbps 250kbps 0.5Mbps 460.8kbps 921.6kbps
Note: 1. UBRRn = 0, error = 0.0%
Table 17-11. Examples of UBRRn Settings for Commonly Used Oscillator Frequencies (Continued)
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
UBRRn Error UBRRn Error UBRRn Error UBRRn Error UBRRn Error UBRRn 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%
19.2k 25 0.2% 51 0.2% 35 0.0% 71 0.0% 47 0.0% 95 0.0%
28.8k 16 2.1% 34 –0.8% 23 0.0% 47 0.0% 31 0.0% 63 0.0%
38.4k 12 0.2% 25 0.2% 17 0.0% 35 0.0% 23 0.0% 47 0.0%
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 – – 0 0.0% – – – – 0 –7.8% 1 –7.8%
Max.
(1)
0.5Mbps 1Mbps 691.2kbps 1.3824Mbps 921.6kbps 1.8432Mbps
Note: 1. UBRRn = 0, error = 0.0%