[avrdude-dev] Cannot program efuse

[Shaun Jackman]

On my current design, I cannot write the efuse reliably, but I can
write the hfuse and lfuse. I'm using an AVR Dragon with a AT90PWM3B.
The AVR Dragon has the most recent firmware (version HW 0106 SW 0101
0109). I can write all the fuses reliably using AVR Studio 4.13 build
528. Do you have any suggestion on how to troubleshoot? I'm using
avrdude 5.4.

Thanks,
Shaun

$ avrdude -Pusb -cdragon_isp -ppwm3b -B99 -Uefuse:w:0xff:m

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.16s

avrdude: Device signature = 0x1e9383
avrdude: reading input file "0xff"
avrdude: writing efuse (1 bytes):

Writing |                                                    | 0%
0.00s ***failed;
Writing | ################################################## | 100% 0.43s

avrdude: 1 bytes of efuse written
avrdude: verifying efuse memory against 0xff:
avrdude: load data efuse data from input file 0xff:
avrdude: input file 0xff contains 1 bytes
avrdude: reading on-chip efuse data:

Reading | ################################################## | 100% 0.05s

avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0000
       0xff != 0x01
avrdude: verification error; content mismatch

avrdude: safemode: efuse changed! Was ff, and is now 1
Would you like this fuse to be changed back? [y/n] n
avrdude: safemode: Fuses OK

avrdude done.  Thank you.