How does the ICD know oscillator frequency?

Will Reeve · Joined: 30 Oct 2003 Posts: 209 Location: Norfolk, England

Hi all,
Does anyone know how the ICD + IDE works out the oscillator frequency of the target?

Will

Guest · Posted: Tue Sep 28, 2004 6:48 am

It does not. When you load the data it's taken from the .H file.

Will Reeve · Joined: 30 Oct 2003 Posts: 209 Location: Norfolk, England

It appears to get it from hardware. If you change the delay statement in the .h it still reads the actual clock rate from the PIC (I am using a U40).

It knows for instance when you enable the PLL x4 in the PIC18 and more importantly if it’s actually active. I have problems a while ago with a new crystal being too strong to lock the PLL, the ICD correctly knew the PIC’s operating speed was just x1 and not x4 the crystal speed!