Datasheet
99
ATmega323(L)
1457E–11/01
Baud
Rate
(bps)
f
osc
= 4.0000 MHz f
osc
= 7.3728 MHz
U2X = 0 U2X = 1 U2X = 0 U2X = 1
UBRR Error UBRR Error UBRR Error UBRR Error
2400 103 0.2% 207 0.2% 191 0.0% 383 0.0%
4800 51 0.2% 103 0.2% 95 0.0% 191 0.0%
9600 25 0.2% 51 0.2% 47 0.0% 95 0.0%
14.4K 16 2.1% 34 -0.8% 31 0.0% 63 0.0%
19.2K 12 0.2% 25 0.2% 23 0.0% 47 0.0%
28.8K 8 -3.5% 16 2.1% 15 0.0% 31 0.0%
38.4K 6 -7.0% 12 0.2% 11 0.0% 23 0.0%
57.6K 3 8.5% 8 -3.5% 7 0.0% 15 0.0%
76.8K 2 8.5% 6 -7.0% 5 0.0% 11 0.0%
115.2K 1 8.5% 3 8.5% 3 0.0% 7 0.0%
230.4K 0 8.5% 1 8.5% 1 0.0% 3 0.0%
250K 0 0.0% 1 0.0% 1 -7.8% 3 -7.8%
0.5M ––0 0.0% 0 -7.8% 1 -7.8%
1M ––––––0-7.8%
Max 250 Kbps 0.5 Mbps 460.8 Kpbs 921.6 Kbps
Baud
Rate
(bps)
f
osc
= 8.0000 MHz
U2X = 0 U2X = 1
UBRR Error UBRR Error
2400 207 0.2% 416 -0.1%
4800 103 0.2% 207 0.2%
9600 51 0.2% 103 0.2%
14.4K 34 -0.8% 68 0.6%
19.2K 25 0.2% 51 0.2%
28.8K 16 2.1% 34 -0.8%
38.4K 12 0.2% 25 0.2%
57.6K 8 -3.5% 16 2.1%
76.8K 6 -7.0% 12 0.2%
115.2K 3 8.5% 8 -3.5%
230.4K 1 8.5% 3 8.5%
250K 1 0.0% 3 0.0%
0.5M 0 0.0% 1 0.0%
1M - - 0 0.0%
Max 0.5 Mbps 1 Mbps
Table 36. Examples of UBRR Settings for Commonly Used Oscillator Frequencies –
UBRR = 0, Error = 0.0% (Continued)