23 Boot Loader Support – Read-While-Write Self-Programming ......... 225
23.1 Boot Loader Features ........................................................................................225
23.2 Application and Boot Loader Flash Sections .....................................................225
23.3 Read-While-Write and No Read-While-Write Flash Sections ............................225
23.4 Boot Loader Lock Bits .......................................................................................228
23.5 Entering the Boot Loader Program ....................................................................229
23.6 Addressing the Flash During Self-Programming ...............................................233
23.7 Self-Programming the Flash ..............................................................................233
24 debugWIRE On-chip Debug System .................................................. 241
24.1 Features ............................................................................................................241
24.2 Overview ............................................................................................................241
24.3 Physical Interface ..............................................................................................241
24.4 Software Break Points .......................................................................................242
24.5 Limitations of debugWIRE .................................................................................242
24.6 debugWIRE Related Register in I/O Memory ....................................................242
25 Memory Programming ......................................................................... 243
25.1 Program And Data Memory Lock Bits ...............................................................243
25.2 Fuse Bits ............................................................................................................244
25.3 Signature Bytes .................................................................................................246
25.4 Calibration Byte .................................................................................................246
25.5 Parallel Programming Parameters, Pin Mapping, and Commands ...................246
25.6 Parallel Programming ........................................................................................249
25.7 Serial Downloading ............................................................................................257
25.8 Serial Programming Pin Mapping ......................................................................257
26 Electrical Characteristics .................................................................... 262
26.1 Absolute Maximum Ratings* .............................................................................262
26.2 DC Characteristics .............................................................................................262
26.3 External Clock Drive Waveforms .......................................................................264
26.4 External Clock Drive ..........................................................................................264
26.5 Maximum speed vs. VCC ...........................................................................................................................265
26.6 SPI Timing Characteristics ................................................................................265
26.7 Hardware Boot EntranceTiming Characteristics ................................................266
27 AT90USB82/162 Typical Characteristics – Preliminary Data ........... 268
27.1 Input Voltage Levels ..........................................................................................269
27.2 Output Voltage Levels .......................................................................................271
5
AT90USB82/162
7707D–AVR–07/08
ATMEL [ ATMEL ]
