ATmega8(L)
8-bit Timer/Counter Register Description ......................................................... 115
Asynchronous Operation of the Timer/Counter ................................................ 117
Timer/Counter Prescaler................................................................................... 121
Serial Peripheral Interface – SPI..................................................... 122
SS Pin Functionality.......................................................................................... 126
Data Modes ...................................................................................................... 129
USART .............................................................................................. 130
Overview........................................................................................................... 130
Clock Generation.............................................................................................. 131
Frame Formats ................................................................................................. 134
USART Initialization.......................................................................................... 135
Data Transmission – The USART Transmitter ................................................. 137
Data Reception – The USART Receiver .......................................................... 140
Asynchronous Data Reception ......................................................................... 144
Multi-processor Communication Mode ............................................................. 148
Accessing UBRRH/UCSRC Registers.............................................................. 149
USART Register Description ............................................................................ 150
Examples of Baud Rate Setting........................................................................ 156
Two-wire Serial Interface ................................................................ 160
Features............................................................................................................ 160
Two-wire Serial Interface Bus Definition........................................................... 160
Data Transfer and Frame Format..................................................................... 161
Multi-master Bus Systems, Arbitration and Synchronization............................ 164
Overview of the TWI Module ............................................................................ 166
TWI Register Description.................................................................................. 168
Using the TWI................................................................................................... 171
Transmission Modes......................................................................................... 175
Multi-master Systems and Arbitration............................................................... 188
Analog Comparator ......................................................................... 190
Analog Comparator Multiplexed Input .............................................................. 192
Analog-to-Digital Converter............................................................ 193
Features............................................................................................................ 193
Starting a Conversion ....................................................................................... 195
Prescaling and Conversion Timing................................................................... 195
Changing Channel or Reference Selection ...................................................... 197
ADC Noise Canceler......................................................................................... 198
ADC Conversion Result.................................................................................... 202
3
2486M–AVR–12/03
ATMEL [ ATMEL ]
