ATmega6490A Atmel Corporation, ATmega6490A Datasheet - Page 195

• Manufacturer Part Number: ATmega6490A
• Manufacturer: Atmel Corporation

Specifications of ATmega6490A

• Flash (kbytes): 64 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 69
• Ext Interrupts: 32
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Segment Lcd: 160
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

20.10 Examples of Baud Rate Setting
Table 20-4.
1.
8284D–AVR–6/11
Baud
Rate
(bps)
Max.
115.2k
230.4k
14.4k
19.2k
28.8k
38.4k
57.6k
76.8k
2400
4800
9600
250k
(1)
UBRR = 0, Error = 0.0%
UBRRn
25
12
6
3
2
1
1
0
–
–
–
–
Examples of UBRRn Settings for Commonly Used Oscillator Frequencies
U2Xn = 0
62.5kbps
ATmega169A/PA/329A/PA/3290A/PA/649A/P/6490A/P
f
Error
-18.6%
osc
-7.0%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
–
–
= 1.0000MHz
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
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
chronous Operational Range” on page
equation:
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
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
192). The error values are calculated using the following
UBRRn
BaudRate
95
47
23
15
11
230.4kbps
7
5
3
2
1
0
–
U2Xn = 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
osc
-18.6%
-3.5%
-7.0%
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
Table 20-3 on page
–
–
= 2.0000MHz
UBRRn
103
51
25
16
12
8
6
3
2
1
–
0
U2Xn = 1
250kbps
Error
-3.5%
-7.0%
”Asyn-
0.2%
0.2%
0.2%
2.1%
0.2%
8.5%
8.5%
8.5%
0.0%
–
193.
195