ATxmega256A3BU Atmel Corporation, ATxmega256A3BU Datasheet - Page 221

• Manufacturer Part Number: ATxmega256A3BU
• Manufacturer: Atmel Corporation

Specifications of ATxmega256A3BU

• Flash (kbytes): 256 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 47
• Ext Interrupts: 49
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 8
• Twi (i2c): 2
• Uart: 6
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 16
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 16
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.6 to 3.6
• Operating Voltage (vcc): 1.6 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 7
• Output Compare Channels: 22
• Input Capture Channels: 22
• Pwm Channels: 22
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

18.3.10
18.3.11
8331A–AVR–07/11
COMPL – Compare Register Low
COMPH – Compare Register High
The COMPH and COMPL register pair represent the 16-bit value, COMP. COMP is constantly
compared with the counter value (CNT). A compare match will set COMPIF in the INTFLAGS
register. Reading and writing 16-bit values requires special attention. Refer
Registers” on page 12
Due to synchronization between the RTC clock and system clock domains, there is a latency of
two RTC clock cycles from updating the register until this has an effect. Application software
needs to check that the SYNCBUSY flag in the
cleared before writing to this register.
If the COMP value is higher than the PER value, no RTC compare match interrupt requests or
events will ever be generated.
• Bit 7:0 – COMP[7:0]: Compare Register Low Byte
These bits hold the LSB of the 16-bit RTC compare value.
• Bit 7:0 – COMP[15:8]: Compare Register High Byte
These bits hold the MSB of the 16-bit RTC compare value.
Bit
+0x0C
Read/Write
Initial Value
Bit
+0x0D
Read/Write
Initial Value
R/W
R/W
7
0
7
0
for details.
R/W
R/W
6
0
6
0
R/W
R/W
5
0
5
0
R/W
R/W
4
0
4
0
COMP[15:8]
COMP[7:0]
”STATUS – Status Register” on page 218
R/W
R/W
Atmel AVR XMEGA AU
3
0
3
0
R/W
R/W
2
0
2
0
R/W
R/W
1
0
1
0
”Accessing 16-bit
R/W
R/W
0
0
0
0
COMPH
COMPL
221
is