ATxmega256A3U Atmel Corporation, ATxmega256A3U Datasheet - Page 214

• 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

17.3
17.3.1
17.4
8331A–AVR–07/11
Address
+0x00
Register Description
Register Summary
CTRLA – Hi-Res Control Register A
Name
CTRLA
The hi-res extension will not output any pulse shorter than one peripheral clock cycle; i.e., a
compare value lower than four will have no visible output.
• Bit 7:3 – Reserved
These bits are reserved and will always be read as zero. For compatibility with future devices,
always write these bits to zero when this register is written.
• Bit 2 – HRPLUS: High Resolution Plus
Setting this bit enables high resolution plus. Hi-res plus is the same as hi-res, but will increase
the resolution by eight (3 bits) instead of four.
The extra resolution is achieved by operating at both edges of the peripheral 4x clock.
• Bit 1:0 – HREN[1:0]: High Resolution Enable
These bits enables the high-resolution mode for a timer/counter according to
Setting one or both HREN bits will enable high-resolution waveform generation output for the
entire general purpose I/O port. This means that both timer/counters connected to the same port
must enable hi-res if both are used for generating PWM or FRQ output on pins.
Table 17-1.
Bit
+0x00
Read/Write
Initial Value
Bit 7
–
HREN[1:0]
High Resolution Enable
00
01
10
11
Bit 6
R
7
–
0
–
R
6
–
0
Bit 5
–
High Resolution Enabled
None
Timer/counter 0
Timer/counter 1
Both timer/counters
R
5
–
0
Bit 4
–
R
4
–
0
Bit 3
–
Atmel AVR XMEGA AU
R
3
–
0
HRPLUS
Bit 2
HRPLUS
R/W
2
0
Bit 1
R/W
1
0
HREN[1:0]
HREN[1:0]
Table
R/W
Bit 0
0
0
17-1.
CTRLA
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