ATmega168A Atmel Corporation, ATmega168A Datasheet - Page 197

• Manufacturer Part Number: ATmega168A
• Manufacturer: Atmel Corporation

Specifications of ATmega168A

• Flash (kbytes): 16 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• 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: Yes
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• 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: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Examples of UBRRn Settings for Commonly Used Oscillator Frequencies
Note:
8271D–AVR–05/11
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)
1. UBRRn = 0, Error = 0.0%
UBRRn
25
12
6
3
2
1
1
0
–
–
–
–
U2Xn = 0
62.5kbps
f
Error
-18.6%
-7.0%
osc
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
–
–
= 1.0000MHz
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
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%
–
–
194). The error values are calculated using the following equation:
ATmega48A/PA/88A/PA/168A/PA/328/P
UBRRn
47
23
11
7
5
3
2
1
1
0
–
–
115.2kbps
U2Xn = 0
Error[%]
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
U2Xn = 1
7
5
3
1
0
–
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
100%
8
6
3
2
1
1
0
–
–
U2Xn = 0
125kbps
”Asynchronous Operational
f
Error
osc
-18.6%
-3.5%
-7.0%
0.2%
0.2%
0.2%
8.5%
8.5%
8.5%
8.5%
–
–
= 2.0000MHz
UBRRn
103
51
25
16
12
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%
–
197