ATmega328P datasheet(444/448 Pages) ATMEL

444 / 448 page

8161D–AVR–10/09

ATmega48PA/88PA/168PA/328P

8-bit Timer/Counter2 with PWM and Asynchronous Operation ...... 144

17.1Features ..............................................................................................................144

17.2Overview .............................................................................................................144

17.3Timer/Counter Clock Sources .............................................................................145

17.4Counter Unit ........................................................................................................145

17.5Output Compare Unit ..........................................................................................146

17.6Compare Match Output Unit ................................................................................148

17.7Modes of Operation .............................................................................................149

17.8Timer/Counter Timing Diagrams .........................................................................153

17.9Asynchronous Operation of Timer/Counter2 .......................................................155

17.10Timer/Counter Prescaler ...................................................................................156

17.11Register Description ..........................................................................................158

SPI – Serial Peripheral Interface ......................................................... 166

18.1Features ..............................................................................................................166

18.2Overview .............................................................................................................166

18.3SS Pin Functionality ............................................................................................171

18.4Data Modes .........................................................................................................171

18.5Register Description ............................................................................................173

USART0 ................................................................................................. 176

19.1Features ..............................................................................................................176

19.2Overview .............................................................................................................176

19.3Clock Generation .................................................................................................177

19.4Frame Formats ....................................................................................................180

19.5USART Initialization ............................................................................................182

19.6Data Transmission – The USART Transmitter ....................................................183

19.7Data Reception – The USART Receiver .............................................................186

19.8Asynchronous Data Reception ............................................................................190

19.9Multi-processor Communication Mode ................................................................193

19.10Register Description ..........................................................................................195

19.11Examples of Baud Rate Setting ........................................................................199

USART in SPI Mode ............................................................................. 204

20.1Features ..............................................................................................................204

20.2Overview .............................................................................................................204

20.3Clock Generation .................................................................................................204

20.4SPI Data Modes and Timing ...............................................................................205

ATmega328P Datasheet(PDF) 444 Page - ATMEL Corporation