ATMEGA64A-MNR Atmel, ATMEGA64A-MNR Datasheet - Page 42

• Manufacturer Part Number: ATMEGA64A-MNR
• Description: IC MCU AVR 64K FLASH 8QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA64A-MNR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: SPI, UART, I2C
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 53
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Operating Temperature Range: - 40 C to + 85 C
• Processor To Be Evaluated: ATMEGA64A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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