Atmel AVR XMEGA AU series - Page 503

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8331B–AVR–03/12
Atmel AVR XMEGA AU
9.1 Features ........................................................................................................113
9.2 Overview ........................................................................................................113
9.3 Reset Sequence ............................................................................................114
9.4 Reset Sources ...............................................................................................115
9.5 Register Description ......................................................................................119
9.6 Register Summary .........................................................................................120
10 Battery Backup System ....................................................................... 121
10.1 Features ........................................................................................................121
10.2 Overview ........................................................................................................121
10.3 Battery Backup System .................................................................................122
10.4 Configuration .................................................................................................123
10.5 Operation .......................................................................................................123
10.6 Register Description ......................................................................................125
10.7 Register Summary .........................................................................................127
11 WDT – Watchdog Timer ....................................................................... 128
11.1 Features ........................................................................................................128
11.2 Overview ........................................................................................................128
11.3 Normal Mode Operation ................................................................................128
11.4 Window Mode Operation ...............................................................................129
11.5 Watchdog Timer Clock ..................................................................................129
11.6 Configuration Protection and Lock ................................................................130
11.7 Registers Description ....................................................................................130
11.8 Register Summary .........................................................................................133
12 Interrupts and Programmable Multilevel Interrupt Controller ......... 134
12.1 Features ........................................................................................................134
12.2 Overview ........................................................................................................134
12.3 Operation .......................................................................................................134
12.4 Interrupts .......................................................................................................135
12.5 Interrupt level .................................................................................................138
12.6 Interrupt priority .............................................................................................138
12.7 Interrupt vector locations ...............................................................................140
12.8 Register Description ......................................................................................141
12.9 Register Summary .........................................................................................142
13 I/O Ports ................................................................................................ 143
13.1 Features ........................................................................................................143