ATMEGA128-16AU SL383 Atmel, ATMEGA128-16AU SL383 Datasheet - Page 194

• Manufacturer Part Number: ATMEGA128-16AU SL383
• Manufacturer: Atmel

Examples of Baud
Rate Setting
Table 82. Examples of UBRR Settings for Commonly Used Oscillator Frequencies
1.
194
Baud
Rate
(bps)
2400
4800
9600
14.4k
19.2k
28.8k
38.4k
57.6k
76.8k
115.2k
230.4k
250k
Max
(1)
UBRR = 0, Error = 0.0%
ATmega128
UBRR
25
12
6
3
2
1
1
0
–
–
–
–
62.5 kbps
U2X = 0
f
-18.6%
osc
-7.0%
Error
8.5%
8.5%
0.2%
0.2%
8.5%
8.5%
–
–
–
–
= 1.0000 MHz
For standard crystal and resonator frequencies, the most commonly used baud rates for asyn-
chronous operation can be generated by using the UBRR settings in
which yield an actual baud rate differing less than 0.5% from the target baud rate, are bold in the
table. Higher error ratings are acceptable, but the receiver will have less noise resistance when
the error ratings are high, especially for large serial frames (see
Range” on page
UBRR
51
25
12
8
6
3
2
1
1
0
–
–
125 kbps
U2X = 1
-18.6%
-3.5%
-7.0%
Error
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
186). The error values are calculated using the following equation:
UBRR
47
23
11
7
5
3
2
1
1
0
–
–
115.2 kbps
U2X = 0
Error[%]
f
-25.0%
osc
Error
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
–
–
= 1.8432 MHz
=
⎛
⎝
BaudRate
------------------------------------------------------- - 1
UBRR
95
47
23
15
11
BaudRate
7
5
3
2
1
0
–
230.4 kbps
U2X = 1
Closest Match
Error
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
–
–
UBRR
⎞
⎠
51
25
12
•
8
6
3
2
1
1
0
–
–
125 kbps
100%
U2X = 0
“Asynchronous Operational
f
-18.6%
osc
-3.5%
-7.0%
Error
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
Table
–
–
= 2.0000 MHz
82. UBRR values
UBRR
103
16
12
51
25
8
6
3
2
1
–
0
2467S–AVR–07/09
250 kbps
U2X = 1
-3.5%
-7.0%
Error
2.1%
0.2%
8.5%
8.5%
8.5%
0.2%
0.2%
0.2%
0.0%
–