Pic16f877a

[Nanya]

Hi guys,

I just wanted to ask. Does a PIC16F877A MCU need a 20MHz crystal oscillator or you can use any crystal even those that have a frequency as low as 4MHz or 1MHz???

Thanks,
Nanya

 

[Diver300]

Most PICs, including the PIC16F877A, can be clocked as slowly as you want.

The biggest problem with running slowly is getting crystals that low to run properly. If you need to run below about 4 MHz, I would suggest:-

RC oscillator
External crystal oscilator that contains a divider
Watch crystal

Watch crystals are a totally different form of crystal to the other types, and most PICs have a setting designed just to drive those.

 

[blueroomelectronics]

If you don't care about the frequency and just want something that runs you can use a resistor & capacitor as a clock.
Or better yet a 16f887

 

[Nigel Goodwin]

Most PICs, including the PIC16F877A, can be clocked as slowly as you want.

Even down to DC! - which means you can single step the PIC clock.