ATmega64A Atmel Corporation, ATmega64A Datasheet - Page 42

• Manufacturer Part Number: ATmega64A
• Manufacturer: Atmel Corporation

Specifications of ATmega64A

• 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

8.7
8.8
8160C–AVR–07/09
Calibrated Internal RC Oscillator
External Clock
The calibrated internal RC Oscillator provides a fixed 1.0, 2.0, 4.0, or 8.0 MHz clock. All frequen-
cies are nominal values at 5V and 25⋅C. This clock may be selected as the system clock by
programming the CKSEL Fuses as shown in
nal components. The CKOPT Fuse should always be unprogrammed when using this clock
option. During reset, hardware loads the calibration byte into the OSCCAL Register and thereby
automatically calibrates the RC Oscillator. At 5V, 25⋅C and 1.0 MHz Oscillator frequency
selected, this calibration gives a frequency within ± 3% of the nominal frequency. Using run-time
calibration methods as described in application notes available at www.atmel.com/avr it is possi-
ble to achieve ± 1% accuracy at any given V
as the chip clock, the Watchdog Oscillator will still be used for the Watchdog Timer and for the
Reset Time-out. For more information on the preprogrammed calibration value, see the section
“Calibration Byte” on page
Table 8-7.
Note:
When this Oscillator is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 8-8.
Note:
To drive the device from an external clock source, XTAL1 should be driven as shown in
8-5. To run the device on an external clock, the CKSEL Fuses must be programmed to “0000”.
By programming the CKOPT Fuse, the user can enable an internal 36 pF capacitor between
XTAL1 and GND.
SUT1:0
10
00
01
11
(1)
8-8. XTAL1 and XTAL2 should be left unconnected (NC).
1. The device is shipped with this option selected.
1. The device is shipped with this option selected.
CKSEL3:0
Internal Calibrated RC Oscillator Operating Modes
Start-up Times for the Internal Calibrated RC Oscillator Clock Selection
Start-up Time from Power-
0001
0010
0011
0100
down and Power-save
(1)
6 CK
6 CK
6 CK
298.
CC
Table
Additional Delay from
Reset (V
and Temperature. When this Oscillator is used
Reserved
8-7. If selected, it will operate with no exter-
4.1 ms
65 ms
Nominal Frequency (MHz)
CC
–
= 5.0V)
1.0
2.0
4.0
8.0
Recommended Usage
BOD enabled
Fast rising power
Slowly rising power
ATmega64A
Figure
42