Datasheet
i
2586D–AVR–02/06
ATtiny25/45/85
Table of Contents
Features..................................................................................................... 1
1 Pin Configurations ................................................................................... 2
1.1 Disclaimer .................................................................................................................2
2 Overview ................................................................................................... 3
2.1 Block Diagram ..........................................................................................................3
2.2 Pin Descriptions .......................................................................................................4
3 Resources ................................................................................................. 5
4 About Code Examples ............................................................................. 5
5 AVR CPU Core .......................................................................................... 6
5.1 Introduction ...............................................................................................................6
5.2 Architectural Overview .............................................................................................6
5.3 ALU – Arithmetic Logic Unit .....................................................................................7
5.4 Status Register .........................................................................................................7
5.5 General Purpose Register File .................................................................................9
5.6 Stack Pointer ..........................................................................................................10
5.7 Instruction Execution Timing ..................................................................................10
5.8 Reset and Interrupt Handling .................................................................................11
6 AVR Memories ........................................................................................ 14
6.1 In-System Re-programmable Flash Program Memory ...........................................14
6.2 SRAM Data Memory ..............................................................................................14
6.3 EEPROM Data Memory .........................................................................................15
6.4 I/O Memory .............................................................................................................21
7 System Clock and Clock Options ......................................................... 22
7.1 Clock Systems and their Distribution ......................................................................22
7.2 Clock Sources ........................................................................................................24
7.3 Default Clock Source ..............................................................................................24
7.4 Crystal Oscillator ....................................................................................................24
7.5 Low-frequency Crystal Oscillator ............................................................................26
7.6 Calibrated Internal RC Oscillator ............................................................................26
7.7 External Clock ........................................................................................................28
7.8 128 kHz Internal Oscillator .....................................................................................29
7.9 Clock Output Buffer ................................................................................................29