ATmega64 Atmel Corporation, ATmega64 Datasheet - Page 42

• Manufacturer Part Number: ATmega64
• Manufacturer: Atmel Corporation

Specifications of ATmega64

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• 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): 4
• Eeprom (bytes): 2048
• 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: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

External RC
Oscillator
2490Q–AVR–06/10
For timing insensitive applications, the external RC configuration shown in
used. The frequency is roughly estimated by the equation f = 1/(3RC). C should be at least 22
pF. By programming the CKOPT Fuse, the user can enable an internal 36 pF capacitor between
XTAL1 and GND, thereby removing the need for an external capacitor.
Figure 20. 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 11. External RC Oscillator Operating Modes
When this Oscillator is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 12. Start-up Times for the External RC Oscillator Clock Selection
Note:
SUT1..0
00
01
10
11
12.
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)
C
R
V
CC
Additional Delay
(V
from Reset
CC
NC
4.1 ms
4.1 ms
65 ms
= 5.0V)
–
Frequency Range (MHz)
Recommended Usage
BOD enabled
Fast rising power
Slowly rising power
Fast rising power or BOD enabled
8.0 - 12.0
0.1 - 0.9
0.9 - 3.0
3.0 - 8.0
XTAL2
XTAL1
GND
ATmega64(L)
Table
Figure 20
11.
can be
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