Can someone explain this to me?
I am developing an AVR multi-tool for myself. it allows you todo basicly anything programming related to an AVR standalone or through serial to PC.
I just added an external clock feature for locked out AVRs. So I hooked up a target, its an attiny2313 set to run on a 8+Mhz external crystal. I loaded it with a simple flip portb on/off every second.
So to test the external clock feature I pulled out the crystal and turn on the clock. So it went from 10Mhz xtal to 1Mhz square wave. The LED is blinking, just alot slower, good. I hit the info button and it output the targets fuse settings so I thought 'sweet the external clock works good enough to read the fuse's it is most likly good enough to write them too.
but. Then I disconnected the external clock source (no clock source now, no crystal) but the tiny's LED is still blinking...
Whats happening? when I put the crystal back in it blinks faster but shouldnt it not be blinking at all?
edit: and when no clock source or crystal i can still read the fusebits too.