ATxmega256A3U Atmel Corporation, ATxmega256A3U Datasheet - Page 186

• Manufacturer Part Number: ATxmega256A3U
• Manufacturer: Atmel Corporation

Specifications of ATxmega256A3U

• 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: 50
• Ext Interrupts: 50
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 10
• Twi (i2c): 2
• Uart: 7
• 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

14.12.15 PERH – Period Register H
14.12.16 CCxL – Compare or Capture x Register L
14.12.17 CCxH – Compare or Capture x Register H
14.12.18 PERBUFL – Timer/Counter Period Buffer L
8331A–AVR–07/11
• Bit 7:0 – PER[15:8]
These bits hold the MSB of the 16-bit period register.
The CCxH and CCxL register pair represents the 16-bit value, CCx. These 16-bit register pairs
have two functions, depending of the mode of operation.
For capture operation, these registers constitute the second buffer level and access point for the
CPU and DMA.
For compare operation, these registers are continuously compared to the counter value. Nor-
mally, the outputs form the comparators are then used for generating waveforms.
CCx registers are updated with the buffer value from their corresponding CCxBUF register when
an UPDATE condition occurs.
• Bit 7:0 – CCx[7:0]
These bits hold the LSB of the 16-bit compare or capture register.
• Bit 7:0 – CCx[15:8]
These bits hold the MSB of the 16-bit compare or capture register.
The PERBUFH and PERBUFL register pair represents the 16-bit value, PERBUF. This 16-bit
register serves as the buffer for the period register (PER). Accessing this register using the CPU
or DMA will affect the PERBUFV flag.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
Bit
+0x27
Read/Write
Initial Value
Bit
+0x36
Read/Write
Initial Value
R/W
R/W
R/W
R/W
7
1
7
0
7
1
7
0
R/W
R/W
R/W
R/W
6
1
6
0
6
1
6
0
R/W
R/W
R/W
R/W
5
1
5
0
5
1
5
0
R/W
R/W
R/W
R/W
4
1
4
0
4
1
4
0
PERBUF[7:0]
PER[15:8]
CCx[7:0]
CCx[15:8]
Atmel AVR XMEGA AU
R/W
R/W
R/W
R/W
3
1
3
0
3
1
3
0
R/W
R/W
R/W
R/W
2
1
2
0
2
1
2
0
R/W
R/W
R/W
R/W
1
1
1
0
1
1
1
0
R/W
R/W
R/W
R/W
0
1
0
0
0
1
0
0
PERBUFL
PERH
CCxL
CCxH
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