Datasheet
Table Of Contents
- Features
- Pin Configuration
- Description
- Architectural Overview
- General-purpose Register File
- ALU – Arithmetic Logic Unit
- Flash Program Memory
- Program and Data Addressing Modes
- Subroutine and Interrupt Hardware Stack
- EEPROM Data Memory
- Memory Access and Instruction Execution Timing
- I/O Memory
- Reset and Interrupt Handling
- ATtiny12 Internal Voltage Reference
- Interrupt Handling
- Sleep Modes for the ATtiny11
- Sleep Modes for the ATtiny12
- ATtiny12 Calibrated Internal RC Oscillator
- Timer/Counter0
- Watchdog Timer
- ATtiny12 EEPROM Read/Write Access
- Analog Comparator
- I/O Port B
- Memory Programming
- Program (and Data) Memory Lock Bits
- Fuse Bits in ATtiny11
- Fuse Bits in ATtiny12
- Signature Bytes
- Calibration Byte in ATtiny12
- Programming the Flash and EEPROM
- High-voltage Serial Programming
- High-voltage Serial Programming Algorithm
- High-voltage Serial Programming Characteristics
- Low-voltage Serial Downloading (ATtiny12 only)
- Low-voltage Serial Programming Characteristics
- Electrical Characteristics
- Register Summary ATtiny11
- Register Summary ATtiny12
- Instruction Set Summary
- Ordering Information
- Packaging Information
- Data Sheet Change Log for ATtiny11/12
- Table of Contents

55
ATtiny11/12
1006D–AVR–07/03
Note: a = address high bits
b = address low bits
H = 0 - Low byte, 1 - High byte
o = data out
i = data in
x = don’t care
1 = Lock bit 1
2 = Lock bit 2
3 = CKSEL0 Fuse
4 = CKSEL1 Fuse
5 = CKSEL2 Fuse
6 = CKSEL3 Fuse
7 = RSTDISBL Fuse
8 = SPIEN Fuse
9 = BODEN Fuse
A = BODLEVEL Fuse
Note: 1. The signature bytes are not readable in Lock mode 3, i.e. both lock bits programmed.
Table 25. Low-voltage Serial Programming Instruction Set
Instruction
Instruction Format
OperationByte 1 Byte 2 Byte 3 Byte4
Programming Enable
1010 1100 0101 0011 xxxx xxxx xxxx xxxx Enable serial programming while
RESET is low.
Chip Erase
1010 1100 100x xxxx xxxx xxxx xxxx xxxx Chip erase Flash and EEPROM
memory arrays.
Read Program Memory
0010 H000 xxxx xxxa bbbb bbbb oooo oooo Read H (high or low) data o from
program memory at word address
a:b.
Write Program Memory
0100 H000 xxxx xxxa bbbb bbbb iiii iiii Write H (high or low) data i to
program memory at word address
a:b.
Read EEPROM
Memory
1010 0000 xxxx xxxx xxbb bbbb oooo oooo Read data o from EEPROM memory
at address b.
Write EEPROM
Memory
1100 0000 xxxx xxxx xxbb bbbb iiii iiii Write data i to EEPROM memory at
address b.
Write Lock Bits
1010 1100 1111 1211 xxxx xxxx xxxx xxxx Write lock bits. Set bits 1,2 = “0” to
program lock bits.
Read Lock Bits
0101 1000 xxxx xxxx xxxx xxxx xxxx x21x Read lock bits. “0” = programmed, “1”
= unprogrammed.
Read Signature Bytes 0011 0000 xxxx xxxx 0000 00bb oooo oooo Read signature byte o at address b.
(1)
Read Calibration Byte 0011 1000 xxxx xxxx 0000 0000 oooo oooo
Write Fuse Bits
1010 1100 101x xxxx xxxx xxxx A987 6543 Set bits A, 9 - 3 = “0” to program, “1”
to unprogram.
Read Fuse Bits
0101 0000 xxxx xxxx xxxx xxxx A987 6543 Read fuse bits. “0” = programmed, “1”
= unprogrammed.