at90ls8535-8mi ATMEL Corporation, at90ls8535-8mi Datasheet - Page 64

• Manufacturer Part Number: at90ls8535-8mi
• Description: 8-bit Microcontroller With 8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Baud Rate Generator
64
AT90S/LS8535
The baud rate generator is a frequency divider which generates baud rates according to
the following equation:
•
•
•
For standard crystal frequencies, the most commonly used baud rates can be generated
by using the UBRR settings in Table 24. UBRR values that yield an actual baud rate dif-
fering less than 2% from the target baud rate are boldface in the table. However, using
baud rates that have more than 1% error is not recommended. High error ratings give
less noise resistance.
Table 24. UBRR Settings at Various Crystal Frequencies (Examples)
Note:
Baud Rate
Baud Rate 3.2768 MHz %Error
Baud Rate 7.3728 MHz %Error
115200 UBRR=
115200 UBRR=
115200 UBRR=
BAUD = Baud rate
f
UBRR = Contents of the UART Baud Rate register, UBRR (0 - 255)
CK
14400 UBRR=
19200 UBRR=
28800 UBRR=
38400 UBRR=
57600 UBRR=
76800 UBRR=
14400 UBRR=
19200 UBRR=
28800 UBRR=
38400 UBRR=
57600 UBRR=
76800 UBRR=
14400 UBRR=
19200 UBRR=
28800 UBRR=
38400 UBRR=
57600 UBRR=
76800 UBRR=
2400 UBRR=
4800 UBRR=
9600 UBRR=
2400 UBRR=
4800 UBRR=
9600 UBRR=
2400 UBRR=
4800 UBRR=
9600 UBRR=
= Crystal clock frequency
Maximum baud rate to each frequency.
1 MHz %Error
191
25
12
84
42
20
13
10
95
47
31
23
15
11
6
3
2
1
1
0
0
0
6
4
3
2
1
7
5
3
22.9 UBRR=
22.9 UBRR=
84.3 UBRR=
12.5 UBRR=
12.5 UBRR=
12.5 UBRR=
0.2 UBRR=
0.2 UBRR=
7.5 UBRR=
7.8 UBRR=
7.8 UBRR=
7.8 UBRR=
7.8 UBRR=
0.4 UBRR=
0.8 UBRR=
1.6 UBRR=
1.6 UBRR=
3.1 UBRR=
1.6 UBRR=
6.3 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
1.8432 MHz %Error
3.6864 MHz %Error
BAUD
8 MHz %Error
207
103
=
47
23
11
95
47
23
15
11
51
34
25
16
12
7
5
3
2
1
1
0
7
5
3
2
1
8
6
3
------------------------------------- -
16(UBRR
33.3 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.2 UBRR=
0.2 UBRR=
0.2 UBRR=
0.8 UBRR=
0.2 UBRR=
2.1 UBRR=
0.2 UBRR=
3.7 UBRR=
7.5 UBRR=
7.8 UBRR=
f
CK
9.216 MHz %Error
+
1 )
2 MHz %Error
4 MHz %Error
103
239
119
51
25
12
51
25
16
12
59
39
29
19
14
8
6
3
2
1
1
0
8
6
3
2
1
9
7
4
22.9 UBRR=
0.2 UBRR=
0.2 UBRR=
0.2 UBRR=
3.7 UBRR=
7.5 UBRR=
7.8 UBRR=
7.8 UBRR=
7.8 UBRR=
7.8 UBRR=
0.2 UBRR=
0.2 UBRR=
0.2 UBRR=
2.1 UBRR=
0.2 UBRR=
3.7 UBRR=
7.5 UBRR=
7.8 UBRR=
7.8 UBRR=
7.8 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
0.0 UBRR=
6.7 UBRR=
0.0 UBRR=
2.4576 MHz %Error
11.059 MHz %Error
4.608 MHz %Error
119
287
143
63
31
15
10
59
29
19
14
71
47
35
23
17
11
1041H–11/01
7
4
3
2
1
0
9
7
4
3
2
8
5
12.5
25.0
20.0
-
0.0
0.0
0.0
3.1
0.0
6.3
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
6.7
0.0
6.7
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0