ATMEGA649-16MUR Atmel, ATMEGA649-16MUR Datasheet - Page 186

• Manufacturer Part Number: ATMEGA649-16MUR
• Description: MCU AVR 64KB FLASH 16MHZ 64QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA649-16MUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.10 Examples of Baud Rate Setting
Table 19-4.
1.
186
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%
ATmega329/3290/649/6490
UBRRn
25
12
6
3
2
1
1
0
–
–
–
–
Examples of UBRRn Settings for Commonly Used Oscillator Frequencies
U2Xn = 0
62.5kbps
f
Error
-18.6%
osc
-7.0%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
–
–
= 1.0000MHz
Do not use Read-Modify-Write instructions (SBI and CBI) to set or clear the MPCMn bit. The
MPCMn bit shares the same I/O location as the TXCn Flag and this might accidentally be
cleared when using SBI or CBI instructions.
For standard crystal and resonator frequencies, the most commonly used baud rates for asyn-
chronous operation can be generated by using the UBRRn settings in
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 resis-
tance when the error ratings are high, especially for large serial frames (see
Operational Range” on page
UBRRn
51
25
12
8
6
3
2
1
1
0
–
–
U2Xn = 1
125kbps
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
–
–
115.2kbps
Error[%]
U2Xn = 0
183). The error values are calculated using the following equation:
f
osc
Error
-25.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
=
–
–
= 1.8432MHz
⎛
⎝
BaudRate
------------------------------------------------------- - 1
UBRRn
BaudRate
95
47
23
15
11
230.4kbps
2
0
–
U2Xn = 1
7
5
3
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%
–
–
UBRRn
⎞
⎠
•
51
25
12
8
6
3
2
1
1
0
–
–
100%
U2Xn = 0
125kbps
f
Error
-18.6%
osc
-3.5%
-7.0%
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
= 2.0000MHz
Table
UBRRn
“Asynchronous
103
19-4. UBRRn
51
25
16
12
2552K–AVR–04/11
8
6
3
2
1
–
0
U2Xn = 1
250kbps
Error
-3.5%
-7.0%
0.2%
0.2%
0.2%
2.1%
0.2%
8.5%
8.5%
8.5%
0.0%
–