ATmega16U4 datasheet(404/408 Pages) ATMEL

404 / 408 page

404

7766D–AVR–01/09

ATmega16U4/ATmega32U4

18.5 Data Transmission – The USART Transmitter ...................................................194

18.6 Data Reception – The USART Receiver ............................................................196

18.7 Asynchronous Data Reception ...........................................................................200

18.8 Multi-processor Communication Mode ...............................................................203

18.9 Hardware Flow Control .......................................................................................204

18.10 USART Register Description ............................................................................206

18.11 Examples of Baud Rate Setting ........................................................................210

USART in SPI Mode ............................................................................. 215

19.1 Overview .............................................................................................................215

19.2 Clock Generation ................................................................................................215

19.3 SPI Data Modes and Timing ...............................................................................216

19.4 Frame Formats ...................................................................................................216

19.5 Data Transfer ......................................................................................................218

19.6 USART MSPIM Register Description .................................................................220

19.7 AVR USART MSPIM vs. AVR SPI .....................................................................222

2-wire Serial Interface .......................................................................... 224

20.1 Features .............................................................................................................224

20.2 2-wire Serial Interface Bus Definition .................................................................224

20.3 Data Transfer and Frame Format .......................................................................225

20.4 Multi-master Bus Systems, Arbitration and Synchronization ..............................228

20.5 Overview of the TWI Module ..............................................................................229

20.6 TWI Register Description ....................................................................................232

20.7 Using the TWI .....................................................................................................235

20.8 Transmission Modes ..........................................................................................239

20.9 Multi-master Systems and Arbitration .................................................................252

USB controller ...................................................................................... 254

21.1 Features .............................................................................................................254

21.2 Block Diagram ....................................................................................................254

21.3 Typical Application Implementation ....................................................................255

21.4 General Operating Modes ..................................................................................258

21.5 Power modes ......................................................................................................260

21.6 Speed Control .....................................................................................................261

21.7 Memory management .........................................................................................261

21.8 PAD suspend ......................................................................................................262

21.9 Plug-in detection .................................................................................................263

ATmega16U4 Datasheet(PDF) 404 Page - ATMEL Corporation