Firmware Upgrade and fuse settings

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erniberni
Posts: 2
Joined: Fri Feb 06, 2015 4:15 pm

Firmware Upgrade and fuse settings

Post by erniberni »

Hi,
today I upgraded the firmware of my DSO 062 to the newest one.
Surprisingly I found the fuse settings when reading with avrdude:
...
avrdude: safemode: lfuse reads as AE
avrdude: safemode: hfuse reads as C1
avrdude: safemode: efuse reads as FF
...
hfuse C1 means the controller is running on internal frequency of 1MHz.
On your firmware support site you note:
Fuse setting: extended byte = 0xFF, high byte = 0xC0, low byte = 0xAE

hfuse C0 means external oscillator, I would have expected a setting for a high frequency crystal as I can find one on the board.
I didn't change the settings and everything still works after the upgrade.

Would it be wise to change the hfuse? Will the software run faster?

Regard
Reinhard
jye1
Posts: 1227
Joined: Wed Feb 20, 2013 4:58 pm

Re: Firmware Upgrade and fuse settings

Post by jye1 »

The LSB bit of fuse high byte is for boot vector setting, not for clock source. This bit is set to 1 for boot to application, i.e. address 0x0000. If this bit is set to 0 it will first boot to bootloader. For DSO062 this bit should be set to 0 if bootloader has been installed. But even bootloader has not been installed, when this bit is set 0 the control may still ends up to address 0x0000 so you won't see problem. If this bit is set to 1 you will not see bootloader at booting.
erniberni
Posts: 2
Joined: Fri Feb 06, 2015 4:15 pm

Re: Firmware Upgrade and fuse settings

Post by erniberni »

Oh sorry, you are right. My bad. I interchanged lfuse and hfuse.
Thanks for your quick reply.

Reinhard
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