[avrdude-dev] con"fuse" bits

[Theodore A. Roth]

Hi,

I'm wondering what the logic behind setting unused fuse bits to 0 before 
display is?

This seems to be confusing behaviour. When you read the fuse bits from a 
device, unused and unprogrammed bits are read as ones and programmed bits 
are zeros. Looking at the printed bytes values and then trying to figure out 
the values from the datasheet seems slightly counter intuitive to me.

>>> d hfuse
avrdude: Send: V [56] X [58] . [08] . [00] . [08]   [20]
avrdude: Recv: . [14]
avrdude: Recv: . [ff]    <<<<<<<< read fuse byte as 0xff
avrdude: Recv: . [10]
0000  07                 <<<<<<<< display fuse byte as 0x0f ???
 
avrdude> d lfuse
>>> d lfuse
avrdude: Send: V [56] P [50] . [00] . [00] . [00]   [20]
avrdude: Recv: . [14]
avrdude: Recv: . [d2]    <<<<<<<<< read as 0xd2
avrdude: Recv: . [10]
0000  c2                 <<<<<<<<< display as 0xc2 ???
 

If there is some compelling reason for this behaviour, it is not obvious to 
me.

Ted Roth