ATtiny20 Atmel Corporation, ATtiny20 Datasheet - Page 9

• Manufacturer Part Number: ATtiny20
• Manufacturer: Atmel Corporation

Specifications of ATtiny20

• Flash (kbytes): 2 Kbytes
• Pin Count: 14
• Max. Operating Frequency: 12 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 5
• Hardware Qtouch Acquisition: Yes
• Max I/o Pins: 12
• Ext Interrupts: 12
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.12
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 3
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

4.4
4.4.1
8235B–AVR–04/11
General Purpose Register File
The X-register, Y-register, and Z-register
The Register File is optimized for the AVR Enhanced RISC instruction set. In order to achieve
the required performance and flexibility, the following input/output schemes are supported by the
Register File:
Figure 4-2
Figure 4-2.
Note:
Most of the instructions operating on the Register File have direct access to all registers, and
most of them are single cycle instructions.
Registers R26:R31 have some added functions to their general purpose usage. These registers
are 16-bit address pointers for indirect addressing of the data space. The three indirect address
registers X, Y, and Z are defined as described in
• One 8-bit output operand and one 8-bit result input
• Two 8-bit output operands and one 8-bit result input
• One 16-bit output operand and one 16-bit result input
A typical implementation of the AVR register file includes 32 general prupose registers but
ATtiny20 implements only 16 registers. For reasons of compatibility the registers are numbered
R16:R31 and not R0:R15.
Registers
Purpose
General
Working
below shows the structure of the 16 general purpose working registers in the CPU.
AVR CPU General Purpose Working Registers
7
R16
R17
R18
R26
R27
R28
R29
R30
R31
…
0
Figure
4-3.
X-register High Byte
Y-register High Byte
Z-register High Byte
X-register Low Byte
Z-register Low Byte
Y-register Low Byte
ATtiny20
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