Datasheet

v
8025M–AVR–6/11
ATmega48P/88P/168P
21.5Frame Formats ....................................................................................................204
21.6Data Transfer ......................................................................................................206
21.7AVR USART MSPIM vs. AVR SPI ......................................................................208
21.8Register Description ............................................................................................209
22 2-wire Serial Interface .......................................................................... 212
22.1Features ..............................................................................................................212
22.22-wire Serial Interface Bus Definition ..................................................................212
22.3Data Transfer and Frame Format ........................................................................214
22.4Multi-master Bus Systems, Arbitration and Synchronization ...............................216
22.5Overview of the TWI Module ...............................................................................219
22.6Using the TWI ......................................................................................................221
22.7Transmission Modes ...........................................................................................225
22.8Multi-master Systems and Arbitration ..................................................................238
22.9Register Description ............................................................................................239
23 Analog Comparator ............................................................................. 244
23.1Overview .............................................................................................................244
23.2Analog Comparator Multiplexed Input .................................................................244
23.3Register Description ............................................................................................245
24 Analog-to-Digital Converter ................................................................ 248
24.1Features ..............................................................................................................248
24.2Overview .............................................................................................................248
24.3Starting a Conversion ..........................................................................................250
24.4Prescaling and Conversion Timing ......................................................................251
24.5Changing Channel or Reference Selection .........................................................253
24.6ADC Noise Canceler ...........................................................................................254
24.7ADC Conversion Result ......................................................................................259
24.8Temperature Measurement .................................................................................259
24.9Register Description ............................................................................................260
25 debugWIRE On-chip Debug System .................................................. 265
25.1Features ..............................................................................................................265
25.2Overview .............................................................................................................265
25.3Physical Interface ................................................................................................265
25.4Software Break Points .........................................................................................266
25.5Limitations of debugWIRE ...................................................................................266
25.6Register Description ............................................................................................266