8-bit AVR Microcontrollers

Programming the Extended Fuse Bits

The algorithm for programming the Extended Fuse bits is as follows (refer to Programming the Flash for details on Command and Data loading):

  1. 1.Step A: Load Command “0100 0000”.
  2. 2.Step C: Load Data Low Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
  3. 3.Set BS1 to “0” and BS2 to “1”. This selects extended data byte.
  4. 4.Give WR a negative pulse and wait for RDY/BSY to go high.
  5. 5.Set BS2 to “0”. This selects low data byte.
Figure 1. Programming the FUSES Waveforms