AT90CAN128-16AE ATMEL Corporation, AT90CAN128-16AE Datasheet - Page 195

• Manufacturer Part Number: AT90CAN128-16AE
• Description: 8-bit Avr Microcontroller With 128K Bytes of Isp Flash And CAN Controller.flash (Kbytes) 128 Vcc (V) 2.7-5.5 EEPROM (Kbytes) 4 SRAM (bytes) 4K CAN (mess. Obj.) 15
• Manufacturer: ATMEL Corporation

Examples of Baud Rate
Setting
Table 84. Examples of UBRRn Settings for Commonly Frequencies
1.
4250C–CAN–03/04
Max.
115.2k
230.4k
Baud
(bps)
14.4k
19.2k
28.8k
38.4k
57.6k
76.8k
2400
4800
9600
Rate
250k
500k
1M
(1)
UBRRn = 0, Error = 0.0%
UBRRn
25
12
6
3
2
1
1
0
–
–
–
–
–
–
62.5 kbps
U2Xn = 0
f
Error
clk
-18.6%
-7.0%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
io
–
–
–
–
–
–
= 1.0000 MHz
UBRRn
51
25
12
8
6
3
2
1
1
0
–
–
–
–
U2Xn = 1
125 kbps
For standard crystal, resonator and external oscillator frequencies, the most commonly
used baud rates for asynchronous operation can be generated by using the UBRRn set-
tings in Table 84 up to Table 87. UBRRn values 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 “Asynchronous Operational Range” on page
186). The error values are calculated using the following equation:
Error
-18.6%
-3.5%
-7.0%
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
–
–
UBRRn
47
23
11
7
5
3
2
1
1
0
–
–
–
–
115.2 kbps
U2Xn = 0
Error
f
clk
-25.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
io
–
–
–
–
Error[%]
= 1.8432 MHz
UBRRn
95
47
23
15
11
=
7
5
3
2
1
0
–
–
–
230.4 Kbps
U2Xn = 1


1
–
Error
BaudRate
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
–
–
–
BaudRate
Closest Match
UBRRn
51
25
12
8
6
3
2
1
1
0
–
–
–
–
U2Xn = 0
125 kpbs
Error
f


clk
-18.6%
-3.5%
-7.0%
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
AT90CAN128
io
100%
–
–
–
–
= 2.0000 MHz
UBRRn
103
51
25
16
12
8
6
3
2
1
–
–
–
–
U2Xn = 1
250 kbps
Error
-3.5%
-7.0%
0.2%
0.2%
0.2%
2.1%
0.2%
8.5%
8.5%
8.5%
–
–
–
–
195