Hello, hopefully someone on this thread might be able to pick up my question, as the present topic is pretty close. In my understanding, a typical uC needs a boot file to specify clocking parameters.
The default clock setting might be, for example, 1 MHz internal, based on an 8 MHz XTAL. Now, if this is true, would one expect to see across the XTAL terminals a square wave at 1 MHz? I have an Atmel uC and assumed it would start its clock on its own, but there is no clock signal present.Thanks.
Yes, most often the factory settings are set to 1MHz internal clocking, the 8MHz/DIV8. So if you want to run at 8MHz, then you do need to change the default fuse settings by burning bootloader. Also note, that it is possible to create an empty bootloader file, so that you only really are burning the fuses for the clock settings.
1) The fuse settings have nothing to do with voltage levels. They are mainly for setting the clock options and booloader options.
2) Before flashing the sketch using Upload using programmer, you need to at least once burn bootloader, mainly to set the fuses for the clock options you are using.