Just a general question about the built in oscillators in most Microchip PICs. All the ones I have seen I think are 4mhz, when the max clock of the chip is usually 20mhz. Why are they never set for maximum speed? Is it just too hard to build that into a single chip or what?
Also, just wanted to clarify, since one instruction cycle happens every 4 clock pulses, I'm pretty sure. So the internal oscillator would make instructions at 1mhz basically, or is the internal oscillator rating saying that the instruction cycle would be 4mhz? (I know, branching instructions take two cycles.)