Forums

486 pll

Started by Unknown July 24, 2005
Does anyone know if the internall PLL on an Intel 80486 can be
by-passed or disabled?

I want to single step using an externally controlled clock without the
PLL.

Thanks,
Wayne
bigwayne@techie.com wrote:
> Does anyone know if the internall PLL on an Intel 80486 can be > by-passed or disabled?
Doubtful unless it's a fully-static core.
> I want to single step using an externally controlled clock without the > PLL. > > Thanks, > Wayne
You can't. The PLL feeds the internal clock. It can't be bypassed.

If you want to single step you *must* use the TAP (Test Access Port)
which is JTAG derived.

There is no other way to do this.