ATtiny26 fuses & lock bits
The fuse bytes set the clock, start-up, brown-out and boot options; the lock bits protect flash and EEPROM. A fuse bit is programmed at 0 . Change a setting and the byte below updates; the starting values are the factory defaults.
PLLCK_SUT_CKSEL Select Clock Source PLL Clock; Start-up time: 1K CK + 0 ms PLL Clock; Start-up time: 1K CK + 4 ms PLL Clock; Start-up time: 1K CK + 64 ms PLL Clock; Start-up time: 16K CK + 64 ms Ext. Clock; Start-up time: 6 CK + 0 ms Int. RC Osc. 1 MHz; Start-up time: 6 CK + 0 ms Int. RC Osc. 2 MHz; Start-up time: 6 CK + 0 ms Int. RC Osc. 4 MHz; Start-up time: 6 CK + 0 ms Int. RC Osc. 8 MHz; Start-up time: 6 CK + 0 ms Ext. RC Osc. - 0.9 MHz; Start-up time: 18 CK + 0 ms Ext. RC Osc. 0.9 MHz - 3.0 MHz; Start-up time: 18 CK + 0 ms Ext. RC Osc. 3.0 MHz - 8.0 MHz; Start-up time: 18 CK + 0 ms Ext. RC Osc. 8.0 MHz - 12.0 MHz; Start-up time: 18 CK + 0 ms Ext. Low-Freq. Crystal; Start-up time: 1K CK + 4 ms Ext. Crystal/Resonator Low Freq.; Start-up time: 258 CK + 4 ms Ext. Crystal/Resonator Low Freq.; Start-up time: 1K CK + 64 ms Ext. Crystal/Resonator Medium Freq.; Start-up time: 258 CK + 4 ms Ext. Crystal/Resonator Medium Freq.; Start-up time: 1K CK + 64 ms Ext. Crystal/Resonator High Freq.; Start-up time: 258 CK + 4 ms Ext. Crystal/Resonator High Freq.; Start-up time: 1K CK + 64 ms Ext. Clock; Start-up time: 6 CK + 4 ms Int. RC Osc. 1 MHz; Start-up time: 6 CK + 4 ms Int. RC Osc. 2 MHz; Start-up time: 6 CK + 4 ms Int. RC Osc. 4 MHz; Start-up time: 6 CK + 4 ms Int. RC Osc. 8 MHz; Start-up time: 6 CK + 4 ms Ext. RC Osc. - 0.9 MHz; Start-up time: 18 CK + 4 ms Ext. RC Osc. 0.9 MHz - 3.0 MHz; Start-up time: 18 CK + 4 ms Ext. RC Osc. 3.0 MHz - 8.0 MHz; Start-up time: 18 CK + 4 ms Ext. RC Osc. 8.0 MHz - 12.0 MHz; Start-up time: 18 CK + 4 ms Ext. Low-Freq. Crystal; Start-up time: 1K CK + 64 ms Ext. Crystal/Resonator Low Freq.; Start-up time: 258 CK + 64 ms Ext. Crystal/Resonator Low Freq.; Start-up time: 16K CK + 0 ms Ext. Crystal/Resonator Medium Freq.; Start-up time: 258 CK + 64 ms Ext. Crystal/Resonator Medium Freq.; Start-up time: 16K CK + 0 ms Ext. Crystal/Resonator High Freq.; Start-up time: 258 CK + 64 ms Ext. Crystal/Resonator High Freq.; Start-up time: 16K CK + 0 ms Ext. Clock; Start-up time: 6 CK + 64 ms Int. RC Osc. 1 MHz; Start-up time: 6 CK + 64 ms Int. RC Osc. 2 MHz; Start-up time: 6 CK + 64 ms Int. RC Osc. 4 MHz; Start-up time: 6 CK + 64 ms Int. RC Osc. 8 MHz; Start-up time: 6 CK + 64 ms Ext. RC Osc. - 0.9 MHz; Start-up time: 18 CK + 64 ms Ext. RC Osc. 0.9 MHz - 3.0 MHz; Start-up time: 18 CK + 64 ms Ext. RC Osc. 3.0 MHz - 8.0 MHz; Start-up time: 18 CK + 64 ms Ext. RC Osc. 8.0 MHz - 12.0 MHz; Start-up time: 18 CK + 64 ms Ext. Low-Freq. Crystal; Start-up time: 32K CK + 64 ms Ext. Crystal/Resonator Low Freq.; Start-up time: 1K CK + 0 ms Ext. Crystal/Resonator Low Freq.; Start-up time: 16K CK + 4 ms Ext. Crystal/Resonator Medium Freq.; Start-up time: 1K CK + 0 ms Ext. Crystal/Resonator Medium Freq.; Start-up time: 16K CK + 4 ms Ext. Crystal/Resonator High Freq.; Start-up time: 1K CK + 0 ms Ext. Crystal/Resonator High Freq.; Start-up time: 16K CK + 4 ms Ext. RC Osc. - 0.9 MHz; Start-up time: 6 CK + 4 ms Ext. RC Osc. 0.9 MHz - 3.0 MHz; Start-up time: 6 CK + 4 ms Ext. RC Osc. 3.0 MHz - 8.0 MHz; Start-up time: 6 CK + 4 ms Ext. RC Osc. 8.0 MHz - 12.0 MHz; Start-up time: 6 CK + 4 ms Ext. Crystal/Resonator Low Freq.; Start-up time: 1K CK + 4 ms Ext. Crystal/Resonator Low Freq.; Start-up time: 16K CK + 64 ms Ext. Crystal/Resonator Medium Freq.; Start-up time: 1K CK + 4 ms Ext. Crystal/Resonator Medium Freq.; Start-up time: 16K CK + 64 ms Ext. Crystal/Resonator High Freq.; Start-up time: 1K CK + 4 ms Ext. Crystal/Resonator High Freq.; Start-up time: 16K CK + 64 ms CKOPT CKOPT fuse (operation dependent of CKSEL fuses) 1 · unprogrammed 0 · programmed HIGH fuse 0xF7 default 0xF7 RSTDISBL Reset Disabled (Enable PB7 as i/o pin) 1 · unprogrammed 0 · programmed SPIEN Serial program downloading (SPI) enabled 1 · unprogrammed 0 · programmed EESAVE Preserve EEPROM through the Chip Erase cycle 1 · unprogrammed 0 · programmed BODLEVEL Brownout detector trigger level Brown-out detection at VCC=4.0 V Brown-out detection at VCC=2.7 V BODEN Brown-out detection enabled 1 · unprogrammed 0 · programmed Lock bits 0xFF default 0xFF LB Memory Lock Further programming and verification disabled Further programming disabled No memory lock features enabled