ATmega644P Atmel Corporation, ATmega644P Datasheet - Page 195

• Manufacturer Part Number: ATmega644P
• Manufacturer: Atmel Corporation

Specifications of ATmega644P

• Flash (kbytes): 64 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 32
• Usb Speed: No
• Usb Interface: No
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• 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: Yes
• 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

Table 16-10. Examples of UBRRn Settings for Commonly Used Oscillator Frequencies (Continued)
1.
8011O–AVR–07/10
Baud
Rate
(bps)
2400
4800
9600
14.4k
19.2k
28.8k
38.4k
57.6k
76.8k
115.2k
230.4k
250k
0.5M
1M
Max.
(1)
UBRR = 0, Error = 0.0%
UBRR
95
47
23
15
11
7
5
3
2
1
0
0
–
–
230.4 Kbps
f
U2Xn = 0
osc
= 3.6864 MHz
Error
-7.8%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
–
–
UBRR
191
95
47
31
23
15
11
7
5
3
1
1
0
–
460.8 Kbps
U2Xn = 1
Error
-7.8%
-7.8%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
–
UBRR
103
51
25
16
12
8
6
3
2
1
0
–
–
0
f
U2Xn = 0
250 Kbps
osc
= 4.0000 MHz
Error
-3.5%
-7.0%
0.2%
0.2%
0.2%
2.1%
0.2%
8.5%
8.5%
8.5%
8.5%
0.0%
–
–
UBRR
207
103
51
34
25
16
12
8
6
3
1
1
0
–
U2Xn = 1
0.5 Mbps
ATmega164P/324P/644P
Error
-0.8%
-3.5%
-7.0%
0.2%
0.2%
0.2%
0.2%
2.1%
0.2%
8.5%
8.5%
0.0%
0.0%
–
UBRR
191
95
47
31
23
15
11
7
5
3
1
1
0
–
460.8 Kbps
f
U2Xn = 0
osc
= 7.3728 MHz
Error
-7.8%
-7.8%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
–
UBRR
191
383
95
63
47
31
23
15
11
7
3
3
1
0
921.6 Kbps
U2Xn = 1
Error
-7.8%
-7.8%
-7.8%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
195