ATmega16U4 datasheet(406/408 Pages) ATMEL

406 / 408 page

406

7766D–AVR–01/09

ATmega16U4/ATmega32U4

25.2 Test Access Port – TAP .....................................................................................315

25.3 TAP Controller ....................................................................................................317

25.4 Using the Boundary-scan Chain .........................................................................318

25.5 Using the On-chip Debug System ......................................................................318

25.6 On-chip Debug Specific JTAG Instructions ........................................................319

25.7 On-chip Debug Related Register in I/O Memory ................................................320

25.8 Using the JTAG Programming Capabilities ........................................................320

25.9 Bibliography ........................................................................................................320

IEEE 1149.1 (JTAG) Boundary-scan ................................................... 321

26.1 Features .............................................................................................................321

26.2 System Overview ................................................................................................321

26.3 Data Registers ....................................................................................................321

26.4 Boundary-scan Specific JTAG Instructions ........................................................323

26.5 Boundary-scan Related Register in I/O Memory ................................................324

26.6 Boundary-scan Chain .........................................................................................325

26.7 ATmega16U4/ATmega32U4 Boundary-scan Order ...........................................328

26.8 Boundary-scan Description Language Files .......................................................331

Boot Loader Support – Read-While-Write Self-Programming ......... 332

27.1 Boot Loader Features .........................................................................................332

27.2 Application and Boot Loader Flash Sections ......................................................332

27.3 Read-While-Write and No Read-While-Write Flash Sections .............................332

27.4 Boot Loader Lock Bits ........................................................................................335

27.5 Entering the Boot Loader Program .....................................................................336

27.6 Addressing the Flash During Self-Programming ................................................339

27.7 Self-Programming the Flash ...............................................................................340

Memory Programming ......................................................................... 348

28.1 Program And Data Memory Lock Bits ................................................................348

28.2 Fuse Bits .............................................................................................................349

28.3 Signature Bytes ..................................................................................................351

28.4 Calibration Byte ..................................................................................................351

28.5 Parallel Programming Parameters, Pin Mapping, and Commands ....................351

28.6 Parallel Programming .........................................................................................354

28.7 Serial Downloading .............................................................................................362

28.8 Serial Programming Pin Mapping .......................................................................363

28.9 Programming via the JTAG Interface .................................................................367

ATmega16U4 Datasheet(PDF) 406 Page - ATMEL Corporation