ATMEGA644PV ATMEL [ATMEL Corporation], ATMEGA644PV Datasheet - Page 404

• Manufacturer Part Number: ATMEGA644PV
• Description: 8-bit Microcontroller with 16/32/64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

iv
ATmega164P/324P/644P
17 USART ................................................................................................... 169
18 USART in SPI Mode ............................................................................. 196
19 2-wire Serial Interface .......................................................................... 205
16.2 Overview ............................................................................................................159
16.3 SS Pin Functionality ...........................................................................................164
16.4 Data Modes ........................................................................................................164
16.5 Register Description ...........................................................................................166
17.1 Features .............................................................................................................169
17.2 USART1 and USART0 .......................................................................................169
17.3 Overview ............................................................................................................169
17.4 Clock Generation ................................................................................................170
17.5 Frame Formats ...................................................................................................173
17.6 USART Initialization ...........................................................................................174
17.7 Data Transmission – The USART Transmitter ...................................................175
17.8 Data Reception – The USART Receiver ............................................................178
17.9 Asynchronous Data Reception ...........................................................................182
17.10 Multi-processor Communication Mode .............................................................185
17.11 Register Description .........................................................................................187
17.12 Examples of Baud Rate Setting .......................................................................192
18.1 Features .............................................................................................................196
18.2 Overview ............................................................................................................196
18.3 Clock Generation ................................................................................................196
18.4 SPI Data Modes and Timing ..............................................................................197
18.5 Frame Formats ...................................................................................................197
18.6 Data Transfer .....................................................................................................199
18.7 AVR USART MSPIM vs. AVR SPI .....................................................................201
18.8 Register Description ...........................................................................................202
19.1 Features .............................................................................................................205
19.2 2-wire Serial Interface Bus Definition .................................................................205
19.3 Data Transfer and Frame Format .......................................................................206
19.4 Multi-master Bus Systems, Arbitration and Synchronization ..............................209
19.5 Overview of the TWI Module ..............................................................................211
19.6 Using the TWI .....................................................................................................213
19.7 Transmission Modes ..........................................................................................216
19.8 Multi-master Systems and Arbitration .................................................................229
8011D–AVR–02/07