Datasheet

vi
2549O–AVR–05/12
ATmega640/1280/1281/2560/2561
28.3 Data Registers ...............................................................................................302
28.4 Boundary-scan Specific JTAG Instructions ...................................................304
28.5 Boundary-scan Chain ....................................................................................305
28.6 Boundary-scan Related Register in I/O Memory ...........................................308
28.7 ATmega640/1280/1281/2560/2561 Boundary-scan Order ............................308
28.8 Boundary-scan Description Language Files ..................................................308
29 Boot Loader Support – Read-While-Write Self-Programming ......... 317
29.1 Features ........................................................................................................317
29.2 Application and Boot Loader Flash Sections .................................................317
29.3 Read-While-Write and No Read-While-Write Flash Sections ........................317
29.4 Boot Loader Lock Bits ...................................................................................320
29.5 Addressing the Flash During Self-Programming ...........................................322
29.6 Self-Programming the Flash ..........................................................................323
29.7 Register Description ......................................................................................332
30 Memory Programming ......................................................................... 335
30.1 Program And Data Memory Lock Bits ...........................................................335
30.2 Fuse Bits ........................................................................................................336
30.3 Signature Bytes .............................................................................................338
30.4 Calibration Byte .............................................................................................338
30.5 Page Size ......................................................................................................338
30.6 Parallel Programming Parameters, Pin Mapping, and Commands ...............338
30.7 Parallel Programming ....................................................................................341
30.8 Serial Downloading ........................................................................................349
30.9 Programming via the JTAG Interface ............................................................354
31 Electrical Characteristics .................................................................... 367
31.1 DC Characteristics .........................................................................................367
31.2 Speed Grades ...............................................................................................369
31.3 Clock Characteristics .....................................................................................371
31.4 External Clock Drive ......................................................................................371
31.5 System and Reset Characteristics ................................................................372
31.6 2-wire Serial Interface Characteristics ...........................................................373
31.7 SPI Timing Characteristics ............................................................................375
31.8 ADC Characteristics – Preliminary Data ........................................................377
31.9 External Data Memory Timing .......................................................................379
32 Typical Characteristics ........................................................................ 385