Re: [avr-gcc-list] Mega128 Fuse Bit setting and uisp

[Dale Seaburg]

Thank you Pieter and Heinrich for your answers.  I had glossed over the
uisp helps dealing with the terminal mode.  Had no idea what it was used
for.  Now I do!  Very convenient.

I'm attaching a log of my session.  My copy of uisp was the latest as of
late the week before this one (version: 20020420).  I've been away from
home this week, so when I saw your responses this afternoon, I
immediately tried it.  Worked great!  My execution line was:
'uisp -dlpt=/dev/parport0 -dprog=stk200 --terminal > uisp.log 2>&1'

Also, note that on page 34 of the datasheet begins some examples of
various cksel and ckout settings.  That's what I had seen, but did not
know how to apply them until now.

Now, for a question to the avr-gcc maintainers.  Is there a progma
section (correct terminology?) that would allow the fuse bits to be set
in the C program being compiled?  If there are methods for defining an
eeprom section, I would think there would be a method to define a fuse
section, too.

Thanks for your help, guys!

Dale.

Heinrich Vermeulen wrote:

> Yes, uisp can program the bits.
> When you use 'uisp -dprog=stk200 -v=3 --terminal' you go into the
> programming terminal mode.
> Type 'ss fuse' to go into the fuse section.
> Then type 'du 0' to see the fuse bits.  The following will be displayed:
> 'Read fuse/cal/lock byte 0 = 0xE1  ---->low byte
> Read fuse/cal/lock byte 1 = 0x99   ---->high byte
> Read fuse/cal/lock byte 2 = 0xA0    ---->can't change it
> Read fuse/cal/lock byte 3 = 0xFF   ---->can't change it
> Read fuse/cal/lock byte 4 = 0xFD'  ---->extended fuse byte
> NOTE - see pg.279 of the datasheet of the M128 for more details on 
the bit
> values and defaults.
>
> To change one of these, just type e.g. 'wr 0 12' to write the value 
12(hex)
> to byte 0.

-------------------------------------------------

{uisp version: 20020420}
{log of terminal mode follows}

Atmel AVR ATmega128 is found.
Entering the AVR Terminal. ?-help, q-quit.
avr>ss fuse
avr>du 0
Out of memory range!
fuse $00000: e1 99 89 ff fd 
avr>wr 0 ef
avr>q
Ouch.