ATtiny26(L)

Table of Contents

Features.................................................................................................

1

Pin Configuration..................................................................................

2

Disclaimer .............................................................................................................

2

Description ............................................................................................

3

Block Diagram ......................................................................................................

4

Pin Descriptions....................................................................................................

5

Architectural Overview.........................................................................

6

General Purpose Register File .............................................................................

7

ALU – Arithmetic Logic Unit..................................................................................

8

In-System Programmable Flash Program Memory ..............................................

9

SRAM Data Memory.............................................................................................

9

Program and Data Addressing Modes................................................................

10

EEPROM Data Memory......................................................................................

14

Memory Access Times and Instruction Execution Timing .............

15

I/O Memory ..........................................................................................

17

Stack Pointer – SP..............................................................................................

19

Reset and Interrupt Handling..............................................................................

20

System Clock and Clock Options .....................................................

25

Clock Systems and their Distribution ..................................................................

25

Clock Sources.....................................................................................................

27

Crystal Oscillator.................................................................................................

28

Low-frequency Crystal Oscillator ........................................................................

29

External RC Oscillator ........................................................................................

30

Calibrated Internal RC Oscillator ........................................................................

31

External Clock.....................................................................................................

32

Power Management and Sleep Modes..............................................

41

Minimizing Power Consumption .........................................................................

43

Timer/Counters ...................................................................................

44

Timer/Counter0 Prescaler...................................................................................

44

Timer/Counter1 Prescaler...................................................................................

45

8-bit Timer/Counter0...........................................................................................

45

8-bit Timer/Counter1...........................................................................................

47

Watchdog Timer..................................................................................

58

EEPROM Read/Write Access.............................................................

60

Preventing EEPROM Corruption ........................................................................

62

i

1477B–AVR–04/02

Universal Serial Interface – USI.........................................................

63

Overview.............................................................................................................

63

Register Descriptions..........................................................................................

64

Functional Descriptions ......................................................................................

68

Alternative USI Usage ........................................................................................

73

Analog Comparator ............................................................................

74

Analog to Digital Converter ...............................................................

77

Features..............................................................................................................

77

Operation ............................................................................................................

78

Prescaling and Conversion Timing .....................................................................

79

ADC Noise Canceler Function............................................................................

82

ADC Conversion Result......................................................................................

82

Scanning Multiple Channels ...............................................................................

88

ADC Noise Canceling Techniques .....................................................................

88

Offset Compensation Schemes ..........................................................................

88

I/O Ports...............................................................................................

90

Introduction .........................................................................................................

90

Ports as General Digital I/O ................................................................................

91

Alternate Port Functions .....................................................................................

95

Register Description for I/O Ports .....................................................................

105

Memory Programming......................................................................

106

Program and Data Memory Lock Bits...............................................................

106

Fuse Bits...........................................................................................................

107

Signature Bytes ................................................................................................

108

Calibration Byte ................................................................................................

108

Parallel Programming Parameters, Pin Mapping, and Commands ..................

108

Parallel Programming .......................................................................................

111

Serial Downloading...........................................................................................

120

Serial Programming Pin Mapping .....................................................................

120

Electrical Characteristics.................................................................

125

Absolute Maximum Ratings*.............................................................................

125

External Clock Drive Waveforms ......................................................................

127

External Clock Drive .........................................................................................

127

ADC Characteristics – Preliminary Data.........................................

128

ATtiny26 Typical Characteristics – Preliminary Data....................

129

ATtiny26/L Register Summary.........................................................

138

Instruction Set Summary .................................................................

139