Manual

ii
ATmega161(L)
1228C–AVR–08/02
Internal Voltage Reference ................................................................ 83
Voltage Reference Enable Signals and Start-up Time ....................................... 83
Interface to External Memory ............................................................ 84
Using the External Memory Interface ................................................................. 88
I/O Ports............................................................................................... 89
Port A.................................................................................................................. 89
Port B.................................................................................................................. 91
Port B Schematics .............................................................................................. 94
Port C.................................................................................................................. 98
Port D................................................................................................................ 100
Port E................................................................................................................ 106
Memory Programming...................................................................... 110
Boot Loader Support......................................................................................... 110
Entering the Boot Loader Program ................................................................... 111
Capabilities of the Boot Loader......................................................................... 112
Self-programming the Flash ............................................................................. 112
Program Memory Lock bits ............................................................. 116
Fuse bits ........................................................................................................... 116
Signature Bytes ................................................................................................ 117
Programming the Flash and EEPROM............................................................. 117
Parallel Programming ....................................................................................... 118
Parallel Programming Characteristics .............................................................. 124
Serial Downloading........................................................................................... 125
Serial Programming Characteristics ................................................................. 129
Electrical Characteristics................................................................. 130
Absolute Maximum Ratings*............................................................................. 130
DC Characteristics............................................................................ 131
External Clock Drive Waveforms ...................................................................... 132
External Data Memory Timing .......................................................................... 133
Typical Characteristics .................................................................... 138
Register Summary............................................................................ 144
Instruction Set Summary ................................................................. 146
Ordering Information........................................................................ 149
Packaging Information ..................................................................... 150
44A ................................................................................................................... 150