ATmega644PR231 Atmel Corporation, ATmega644PR231 Datasheet - Page 120

• Manufacturer Part Number: ATmega644PR231
• Manufacturer: Atmel Corporation

Specifications of ATmega644PR231

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Max I/o Pins: 32
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Crypto Engine: AES
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Operating Voltage (vcc): 1.8 to 3.6
• Timers: 3
• Frequency Band: 2.4 GHz
• Max Data Rate (mb/s): 2
• Antenna Diversity: Yes
• External Pa Control: Yes
• Power Output (dbm): 3
• Receiver Sensitivity (dbm): -101
• Receive Current Consumption (ma): 13.2
• Transmit Current Consumption (ma): 14.4
• Link Budget (dbm): 104

8111C–MCU Wireless–09/09
• Bit [3:0] - XTAL_TRIM
The register bits XTAL_TRIM control two internal capacitance arrays connected to pins XTAL1
and XTAL2. A capacitance value in the range from 0 pF to 4.5 pF is selectable with a resolution
of 0.3 pF.
Table 9-16.
Register Bit
XTAL_TRIM
Crystal Oscillator Trimming Capacitors
Value
0x0
0x1
0xF
...
Description
0.0 pF, trimming capacitors disconnected
0.3 pF trimming capacitor switched on
4.5 pF trimming capacitor switched on
AT86RF231
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