Proteus Simulation- clock fuse bits

Hi everyone. Today i was testing the Micro-controller simulation in Proteus.
I built a circuit as shown below and loaded the .hex file. When i try to simulate it i got an error.

"CKSEL fuse bits specify external oscillator but no clock frequency is specified"

I have used 12MHz crystal and selected external clock source but it isn't working. However, if i select internal clock option ,everything works fine.
Please correct me.

I think you have to change your clock frequency from the 'default' to '12Mhz'(or whatever u want to use) in the advanced settings dialogue box.
Check out the pic. i attached.
Also don't forget to assign the same frequency to the crystal,I mean right click the oscillator and change the clock frequency to 12Mhz(or whatever u want to use).
Try these settings and even then if it didn't workout let me know.

Mystogan said:

I think you have to change your clock frequency from the 'default' to '12Mhz'(or whatever u want to use) in the advanced settings dialogue box.
Check out the pic. i attached.
Also don't forget to assign the same frequency to the crystal,I mean right click the oscillator and change the clock frequency to 12Mhz(or whatever u want to use).
Try these settings and even then if it didn't workout let me know.

Click to expand...

Thanks a lot sir. It worked

Hi all,

Maybe you can help me:

I have project about obtaining a PCB board including ATMEGA microprocessor, but I have a difficulties in bootloading the ATMEGA. In shortly, I have bootloaded a ATMEGA328P-PU by using Arduino as ISP mode. ATMEGA328P-PU works with 16MHz crystal and the necessary capacitor and resistor etc. Everything is OK. However, I have a ATMEGA328P-U, and I have performed the same steps for bootloading. The bootloading process is done, successfully. In this point, I have a problem is that the ATMEGA328P-U works a different frequency I think, but also it may be depending on different cause. It can be explained what I say as follows;

For example, you know a Blink example code in Arduino (LED blinks connected in D13 with 1 sec). Here, ATMEGA328P-PU is OK meaning that the application program (LED Blink) runs, well. But, the ATMEGA328P-U works with different speed meaning that LED blinks with 10 sec, even though I used 16MHz crystal and same circuit components. Why this problem come out and how can I correct/handle this case? Please help