ATmega48 Atmel Corporation, ATmega48 Datasheet - Page 198

• Manufacturer Part Number: ATmega48
• Manufacturer: Atmel Corporation

Specifications of ATmega48

• Flash (kbytes): 4 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• 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: No
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 256
• Self Program Memory: NO
• 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

Table 20-12. Examples of UBRRn settings for commonly used oscillator frequencies.
Note:
2545T–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
0.5M
1M
Max.
(1)
1. UBRRn = 0, error = 0.0%
UBRRn
416
207
103
68
51
34
25
16
12
8
3
3
1
0
U2Xn = 0
1Mbps
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%
= 16.0000MHz
UBRRn
832
416
207
138
103
68
51
34
25
16
8
7
3
1
U2Xn = 1
2Mbps
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
79
59
39
29
19
14
1.152Mbps
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%
= 18.4320MHz
–
–
UBRRn
959
479
239
159
119
79
59
39
29
19
2.304Mbps
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
4
4
–
–
1.25Mbps
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%
= 20.0000MHz
–
–
UBRRn
1041
520
259
173
129
86
64
42
32
21
10
9
4
–
U2Xn = 1
2.5Mbps
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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