ATTINY20-MMHR Atmel, ATTINY20-MMHR Datasheet - Page 9

• Manufacturer Part Number: ATTINY20-MMHR
• Description: MCU AVR 2KB FLASH 12MHZ 20QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY20-MMHR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 12MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 12
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

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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