ATmega8 Atmel Corporation, ATmega8 Datasheet - Page 237

• 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

External Clock
Drive Waveforms
External Clock
Drive
2486Z–AVR–02/11
Figure 114. External Clock Drive Waveforms
Table 99. External Clock Drive
Table 100. External RC Oscillator, Typical Frequencies
Notes:
Symbol
1/t
t
t
t
t
t
Δ
CLCL
CHCX
CLCX
CLCH
CHCL
t
CLCL
CLCL
1. R should be in the range 3kΩ - 100kΩ, and C should be at least 20pF. The C values given in
2. The frequency will vary with package type and board layout
the table includes pin capacitance. This will vary with package type
Parameter
Oscillator Frequency
Clock Period
High Time
Low Time
Rise Time
Fall Time
Change in period from one
clock cycle to the next
R [kΩ]
33
10
V
IL1
(1)
V
IH1
V
CC
Min
125
50
50
0
= 2.7V to
C [pF]
22
22
Max
1.6
1.6
5.5
2
8
V
V
CC
62.5
Min
25
25
0
= 4.5V to
650kHz
2.0MHz
ATmega8(L)
Max
0.5
0.5
16
5.5
2
f
(2)
V
Units
MHz
μs
ns
%
237