Datasheet

vii
7766F–AVR–11/10
ATmega16/32U4
28.6Parallel Programming ..........................................................................................352
28.7Serial Downloading .............................................................................................360
28.8Serial Programming Pin Mapping ........................................................................361
28.9Programming via the JTAG Interface ..................................................................365
29 Electrical Characteristics .................................................................... 378
29.1Absolute Maximum Ratings* ...............................................................................378
29.2DC Characteristics ..............................................................................................378
29.3External Clock Drive Waveforms .........................................................................380
29.4External Clock Drive ............................................................................................380
29.5Maximum speed vs. V
CC ............................................................................................................................. 380
29.62-wire Serial Interface Characteristics .................................................................381
29.7SPI Timing Characteristics ..................................................................................383
29.8Hardware Boot EntranceTiming Characteristics ..................................................384
30 Typical Characteristics ........................................................................ 386
30.1Active Supply Current ..........................................................................................386
30.2Idle Supply Current ..............................................................................................389
30.3Power-down Supply Current ...............................................................................391
30.4Power-save Supply Current ................................................................................392
30.5Pin Pull-Up ..........................................................................................................393
30.6Pin Driver Strength ..............................................................................................394
30.7Pin Threshold and Hysteresis .............................................................................397
30.8BOD Threshold ....................................................................................................400
30.9Internal Oscilllator Speed ....................................................................................402
30.10Current Consumption of Peripheral Units ..........................................................405
30.11Current Consumption in Reset and Reset Pulsewidth ......................................407
31 Register Summary ............................................................................... 408
32 Instruction Set Summary .................................................................... 412
33 Ordering Information ........................................................................... 415
33.1ATmega16U4 ......................................................................................................415
33.2ATmega32U4 ......................................................................................................416
34 Packaging Information ........................................................................ 417
34.1TQFP44 ...............................................................................................................417
34.2QFN44 .................................................................................................................418
35 Errata ..................................................................................................... 419