ATMEGA8_08 Datasheet, PDF (305/308 Pages) ATMEL Corporation – 8-bit with 8K Bytes In-System Programmable Flash

2486T–AVR–05/08
ATmega8(L)
Timer/Counter Clock Sources 105
Counter Unit 106
Output Compare Unit 107
Compare Match Output Unit 109
Modes of Operation 110
Timer/Counter Timing Diagrams 114
8-bit Timer/Counter Register Description 117
Asynchronous Operation of the Timer/Counter 119
Timer/Counter Prescaler 123
Serial Peripheral Interface – SPI 124
SS Pin Functionality 129
Data Modes 132
USART 133
Overview 133
Clock Generation 134
Frame Formats 137
USART Initialization 138
Data Transmission – The USART Transmitter 140
Data Reception – The USART Receiver 143
Asynchronous Data Reception 147
Multi-processor Communication Mode 151
Accessing UBRRH/UCSRC Registers 152
USART Register Description 153
Examples of Baud Rate Setting 159
Two-wire Serial Interface 163
Features 163
Two-wire Serial Interface Bus Definition 163
Data Transfer and Frame Format 164
Multi-master Bus Systems, Arbitration and Synchronization 167
Overview of the TWI Module 169
TWI Register Description 171
Using the TWI 174
Transmission Modes 178
Multi-master Systems and Arbitration 191
Analog Comparator 193
Analog Comparator Multiplexed Input 195
Analog-to-Digital Converter 196
Features 196
Starting a Conversion 198
Prescaling and Conversion Timing 198
Changing Channel or Reference Selection 200
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