17.2 Data Modes ........................................................................................................164
17.3 SPI Register Description ....................................................................................165
18 USART ................................................................................................... 168
18.1 Overview ............................................................................................................169
18.2 Clock Generation ................................................................................................170
18.3 Frame Formats ...................................................................................................173
18.4 USART Initialization ...........................................................................................175
18.5 Data Transmission – The USART Transmitter ...................................................177
18.6 Data Reception – The USART Receiver ............................................................180
18.7 Asynchronous Data Reception ...........................................................................185
18.8 Multi-processor Communication Mode ...............................................................188
18.9 USART Register Description ..............................................................................190
18.10 Examples of Baud Rate Setting .......................................................................195
19 USI – Universal Serial Interface .......................................................... 199
19.1 Overview ............................................................................................................199
19.2 Functional Descriptions ......................................................................................200
19.3 Alternative USI Usage ........................................................................................206
19.4 USI Register Descriptions ..................................................................................207
20 AC - Analog Comparator ..................................................................... 211
20.1 Analog Comparator Multiplexed Input ................................................................212
20.2 Analog Comparator Register Description ...........................................................213
21 ADC - Analog to Digital Converter ..................................................... 215
21.1 Features .............................................................................................................215
21.2 Operation ............................................................................................................216
21.3 Starting a Conversion .........................................................................................217
21.4 Prescaling and Conversion Timing .....................................................................218
21.5 Changing Channel or Reference Selection ........................................................220
21.6 ADC Noise Canceler ..........................................................................................221
21.7 ADC Conversion Result .....................................................................................226
21.8 ADC Register Description ..................................................................................228
22 LCD Controller ..................................................................................... 233
22.1 Features .............................................................................................................233
22.2 Overview ............................................................................................................233
22.3 Mode of Operation ..............................................................................................236
iv
ATmega169P
8018A–AVR–03/06
ATMEL [ ATMEL ]
