ATMEGA644PA-AU Atmel, ATMEGA644PA-AU Datasheet - Page 198

• Manufacturer Part Number: ATMEGA644PA-AU
• Description: IC MCU 8BIT 64KB FLASH 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644PA-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• 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): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: ATMEGA64x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, TWI, UART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 32
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 18-12. Examples of UBRRn Settings for Commonly Used Oscillator Frequencies (Continued)
1.
8272A–AVR–01/10
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
416
207
103
68
51
34
25
16
12
8
3
3
1
0
U2Xn = 0
1 Mbps
f
osc
Error
-0.1%
-0.8%
-3.5%
0.2%
0.2%
0.6%
0.2%
0.2%
2.1%
0.2%
8.5%
0.0%
0.0%
0.0%
= 16.0000 MHz
164A/164PA/324A/324PA/644A/644PA/1284/1284P
UBRR
832
416
207
138
103
68
51
34
25
16
8
7
3
1
U2Xn = 1
2 Mbps
Error
-0.1%
-0.1%
-0.8%
-3.5%
0.0%
0.2%
0.2%
0.2%
0.2%
2.1%
0.0%
0.0%
0.0%
0.6%
UBRR
479
239
119
79
59
39
29
19
14
9
4
4
–
–
1.152 Mbps
U2Xn = 0
f
osc
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%
–
–
= 18.4320 MHz
UBRR
959
479
239
159
119
59
39
29
19
79
2.304 Mbps
9
8
4
–
U2Xn = 1
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%
2.4%
–
UBRR
520
259
129
86
64
42
32
21
15
10
4
4
–
–
1.25 Mbps
U2Xn = 0
f
osc
Error
-0.2%
-1.4%
-1.4%
-1.4%
0.0%
0.2%
0.2%
0.2%
0.9%
1.7%
8.5%
0.0%
–
–
= 20.0000 MHz
UBRR
1041
173
129
520
259
86
64
42
32
21
10
9
4
–
U2Xn = 1
2.5 Mbps
Error
-0.2%
-1.4%
-1.4%
-1.4%
-0.2%
0.0%
0.0%
0.2%
0.2%
0.2%
0.9%
0.0%
0.0%
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