ATMEGA3250-16AUR Atmel, ATMEGA3250-16AUR Datasheet - Page 176

• Manufacturer Part Number: ATMEGA3250-16AUR
• Description: MCU AVR 32K FLASH 16MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA3250-16AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K 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.
2570M–AVR–04/11
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%
UBRR
25
12
6
3
2
1
1
0
–
–
–
–
U2Xn = 0
62.5 kbps
Examples of UBRR Settings for Commonly Used Oscillator Frequencies
f
Error
-18.6%
osc
-7.0%
0.2%
0.2%
8.5%
8.5%
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
–
–
U2Xn = 1
125 kbps
Error
-18.6%
-3.5%
-7.0%
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
173). The error values are calculated using the following equation:
UBRR
47
23
11
7
5
3
2
1
0
–
–
1
115.2 kbps
U2Xn = 0
Error[%]
f
Error
-25.0%
osc
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
U2Xn = 1
ATmega325/3250/645/6450
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
–
–
U2Xn = 0
125 kbps
100%
“Asynchronous Operational
f
Error
-18.6%
osc
-3.5%
-7.0%
Table
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
= 2.0000 MHz
19-4. UBRR values
UBRR
103
51
25
16
12
8
6
3
2
1
–
0
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%
0.0%
–
176