ATmega8 Atmel Corporation, ATmega8 Datasheet - Page 29

• Manufacturer Part Number: ATmega8
• Manufacturer: Atmel Corporation

Specifications of ATmega8

• Flash (kbytes): 8 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 2
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• 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): 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: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 1
• Pwm Channels: 3
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

2486Z–AVR–02/11
least 22pF. By programming the CKOPT Fuse, the user can enable an internal 36pF capacitor
between XTAL1 and GND, thereby removing the need for an external capacitor.
Figure 12. External RC Configuration
The Oscillator can operate in four different modes, each optimized for a specific frequency
range. The operating mode is selected by the fuses CKSEL3..0 as shown in
Table 7. External RC Oscillator Operating Modes
When this Oscillator is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 8. Start-up Times for the External RC Oscillator Clock Selection
Note:
SUT1..0
00
01
10
11
8.
1. This option should not be used when operating close to the maximum frequency of the device
CKSEL3..0
Start-up Time from
Power-down and
0101
0110
0111
1000
Power-save
6 CK
18 CK
18 CK
18 CK
(1)
R
C
V
Additional Delay
CC
(V
from Reset
CC
4.1ms
4.1ms
65ms
= 5.0V)
–
NC
Frequency Range (MHz)
Recommended Usage
BOD enabled
Fast rising power
Slowly rising power
Fast rising power or BOD enabled
XTAL2
XTAL1
GND
8.0 - 12.0
0.1 - 0.9
0.9 - 3.0
3.0 - 8.0
ATmega8(L)
Table
7.
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