ATMEGA48-20AI Atmel, ATMEGA48-20AI Datasheet - Page 197

• Manufacturer Part Number: ATMEGA48-20AI
• Description: IC AVR MCU 4K 5V 20MHZ 32-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA48-20AI

• 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: 23
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 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: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: ATMEGA48-24AI; ATMEGA48-24AI

Table 19-12. Examples of UBRRn Settings for Commonly Used Oscillator Frequencies (Continued)
1.
2545S–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)
UBRRn = 0, Error = 0.0%
UBRRn
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
UBRRn
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%
0.6%
0.2%
0.2%
2.1%
0.0%
0.0%
0.0%
UBRRn
479
239
119
1.152 Mbps
79
59
39
29
19
14
9
4
4
–
–
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
–
–
UBRRn
959
479
239
159
119
2.304 Mbps
79
59
39
29
19
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%
–
UBRRn
520
259
129
86
64
42
32
21
15
10
1.25 Mbps
4
4
–
–
U2Xn = 0
ATmega48/88/168
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
–
–
UBRRn
1041
520
259
173
129
86
64
42
32
21
10
9
4
–
U2Xn = 1
2.5 Mbps
Error
-0.2%
-0.2%
-1.4%
-1.4%
-1.4%
0.0%
0.0%
0.2%
0.2%
0.2%
0.9%
0.0%
0.0%
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