336
7530J–AVR–03/12
Atmel ATmega48/88/168 Automotive
17.9
USART Register Description .........................................................................184
17.10
Examples of Baud Rate Setting .....................................................................188
18
USART in SPI Mode ............................................................................. 192
18.1
Overview ........................................................................................................192
18.2
Clock Generation ...........................................................................................192
18.3
SPI Data Modes and Timing ..........................................................................193
18.4
Frame Formats ..............................................................................................193
18.5
Data Transfer .................................................................................................196
18.6
USART MSPIM Register Description ............................................................198
18.7
AVR USART MSPIM vs. AVR SPI ................................................................200
19
2-wire Serial Interface .......................................................................... 201
19.1
Features ........................................................................................................201
19.2
2-wire Serial Interface Bus Definition ............................................................201
19.3
Data Transfer and Frame Format ..................................................................202
19.4
Multi-master Bus Systems, Arbitration and Synchronization .........................206
19.5
Overview of the TWI Module .........................................................................208
19.6
TWI Register Description ...............................................................................210
19.7
Using the TWI ................................................................................................214
19.8
Transmission Modes .....................................................................................218
19.9
Multi-master Systems and Arbitration ............................................................232
20
Analog Comparator ............................................................................. 233
20.1
Analog Comparator Multiplexed Input ...........................................................236
21
Analog-to-Digital Converter ................................................................ 237
21.1
Features ........................................................................................................237
21.2
Starting a Conversion ....................................................................................239
21.3
Prescaling and Conversion Timing ................................................................240
21.4
Changing Channel or Reference Selection ...................................................243
21.5
ADC Noise Canceler .....................................................................................244
21.6
ADC Conversion Result................................................................................. 249
22
debugWIRE On-chip Debug System .................................................. 254
22.1
Features ........................................................................................................254
22.2
Overview ........................................................................................................254
22.3
Physical Interface ..........................................................................................254
22.4
Software Break Points ...................................................................................255