28X2 external oscillator

[whiteoaks7]

I'm replacing a PIC 16F873 with the 28X2 (I no longer have the masochistic desire to program in either assembler or C!). I find to my delight that the 28X2 has faster oscillators built-in than the old PIC's external oscillator (a 2.4576 xtal). Unfortunately, until the PicAxe is proven I'm not able to throw the PIC away and redesign the circuit; a fact that is leading to more than one bit of shoe-horning. To the point: the old oscillator has to remain to clock the old PICs so will it interfere in some way with the internal clock of the 28X2? Or (hopefully) are the two osc pins (9 and 10) are completely isolated when the internal oscillator is chosen?

Hope you can dig the question out of all this prose... will the external oscillator interfere with the PicAxe's internal one?

Cheers

 

[hippy]

Good news - You should be fine with the crystal left connected while using the internal oscillator. It will operate at the internal oscillator frequency and there should be no interference from the crystal.

 

[srnet]

Having the resonator or crystal there will also keep the sleep current down, even if the external oscillator is not used.

 

[whiteoaks7]

Thanks guys - good news indeed...