I think that I may have selected this setting when I was trying to find the
00xC2 setting in AVRStudio under the fuses tab.
How do I provide an external clock to pin 24 again?
WARNING: DO NOT use the "Ext Clock" setting CKSEL=0000. Doing this will
"brick" your robostix. In order to "unbrick" the robostix you need to
provide an external clock to pin 24 of the ATMega128, and then change the
fuse setting to "Ext Crystal".
From: Dave Hylands <dhylands@gm...> - 2008-03-16 22:19:49
On Sun, Mar 16, 2008 at 2:46 PM, Melanie <melanie.vida@...> wrote:
> While I'm trying to figure out where pin 24 is on the ATmega 128 and how to
> get an external clock to apply to pin 24 I will need to understand the
> following fuse settings as it relates to the options in AVRStudio.
> What setting in the attached image, Fuses.jpg, from AVRStudio, which
> settings will get 0xC2, 0xBF and 0xFF
Start with the setting pictured on this page:
That gives you 0xC9, 0xBF, 0xFF
Then, if you look in the datasheet for the ATMega128 on page 288, they
show which bits correspond to what.
0xC9 = 11001001 which would have OCDEN=1, JTAGEN=1, SPIEN=0, CKOPT=0,
EESAVE=1, BOOTSZ1=0 BOOTSZ0=0, BOOTRST=1
0xC2 = 11000010 which would have OCDEN=1, JTAGEN=1, SPIEN=0, CKOPT=0,
EESAVE=0, BOOTSZ1=0 BOOTSZ0=1, BOOTRST=0
So, to change from 0xC9 to 0xC2, we want to change the EESAVE,
BOOTSZ1, BOOTSZ0, and BOOTRTS fuses.
To set EESAVE=0, you check the "Preserve EEPROM memory through the
Chip Erase cycle; [EESAVE=0]"
To set BOOTSZ1=0 & BOOTSZ0=1, you check the "Boot Flash section size=2048 words"
To set BOOTRST=0, you check the "Boot Reset vector enabled"
Vancouver, BC, Canada